What is homocystinuria ?
Homocystinuria belongs congenital metabolic disorders , patients due to the lack of a normal metabolic enzymes can not be too much homocysteine metabolism of homocysteine accumulation caused by the urine , resulting in high cystamine acidosis . Currently there are three known high homocysteine hyperlipidemia , because of the lack of an enzyme may be :
(1) Cystathionine beta-synthase (CBS) deficiency
(2) 5,10-methylenetetrahydrofolate reductase (MTHFR deficiency)
(3) Cobalamin (Cb1) or vitamin B12 deficiency
Among the first type (CBS deficiency ) the most common , CBS 's role is to metabolize homocysteine into cystathionine, this process requires the involvement of vitamin B6 ; patient serum homocysteine and methionine concentrations are increased. Some patients with this type of treatment can have a role pyridoxin called pyridoxin-reponsive; while some patients but no response , called pyridoxin non-responsive; latter can be used for special diets and other drugs to control .
Type II and type III patients blood and urine homocysteine will increase, but methionine was normal .
Homocystinuria symptoms ?
Homocystinuria may infringe a number of organs :
( 1 ) Eye : dislocaion of the ocular lens, myopia, glaucoma
( 2 ) Bones: Osteoporosis , slender long bones and other skeletal abnormalities
( 3 ) the nervous system: developmental delay , mental retardation , epilepsy , mental disorders , and focal neurologic symptoms
( 4 ) Vascular : Vascular embolization
How to treat ?
Homocystinuria treatment goal is to reduce blood homocysteine and methionine concentrations ; CBS deficiency in about half of patients respond to treatment can pyridoxin , and some conditions are only part of the response.
Use folates, vitamin B12 and betaine adjuvant therapy is a must ; sometimes recommended that low methionine, high- cystine diet. Improve biochemical abnormalities can often appear in the clinical progress and prevent the development of disease ; however be noted that the therapeutic effect is often very slow , and prolonged biochemical abnormalities but often serious and can not reply . Therefore, in addition to medical treatment, special dietary control is also very important.
For the patient 's relatives and descendants , as recommended early screening ; early diagnosis and treatment is very important in order to avoid the damage can not reply .
Sunday
Recognizing high homocysteine
< Concept analysis >
Most high homocysteine due to cystathionine β synthase (cystathionine β-synthase, CBS) loss of function caused by multiple organ disease, manifested as multiple thromboembolism, mental retardation , crystal ectopic , Zhi Zhi Guo long.
< Foreword >
Homocysteine also known as homocysteine (Homocysteine, Hcy), is the intermediate metabolite of methionine . Currently found that high homocysteine is mainly because the encoding methylenetetrahydrofolate reductase (MTHFR), cystathionine synthase (CBS) and other gene mutation , causing enzyme defect or caused by reduced activity . Normal fasting plasma homocysteine concentration was 5 ~ 15μmol / L, according to AHA classification , 15 ~ 30 μmol / L were mild , 30 ~ 100μmol / L , moderate and severe ,> 100μmol / L severe. Methionine > 400μmol / L can cause toxicity.
Studies have shown that 10% of coronary heart disease and elevated homocysteine , can cause mild to moderately elevated risk of death from cardiovascular disease increased 4-6 times , so now the blood homocysteine disorders as atherosclerosis and coronary heart disease an independent risk factor.
< Etiology >
The disease mainly there are three common biochemical defect type :
Deficient
The main reason
Cystathionine β
Synthase
Deficient
( Synthase deficiency type )
The most common type
Due to cystathionine synthase (CBS) deficiency (cystathionine beta synthase deficiency), homocysteine into cystathionine pathway is blocked → homocysteine can be metabolized in the blood , urine large accumulation homocysteine and methionine increased blood clotting factor → further action , as well as affect protein metabolism and collagen fiber structure → causing lens dislocation , osteoporosis , fractures, mental retardation , multiple vascular occlusion , arterial thrombosis
[Note] Vitamin B6 is cystathionine synthase (CBS) coenzyme
Methylenetetrahydrofolate -
Homocysteine A
Transferase enzyme deficiency type
Because homocysteine into methionine metabolic pathway disorder . Methyltransferase activity itself is normal, but it is a coenzyme ( vitamin B12) deficiencies. Blood and urine increased homocysteine , methionine in the blood is not increased ; blood and urine increased cystathionine
[Note] Vitamin B12 is a coenzyme methyl transferase
N5, N10- methylenetetrahydrofolate
Folate reductase deficiency type
( Reductase deficiency type )
Methylenetetrahydrofolate reductase deficiency (MTHFR), can not lead to methylation of homocysteine in blood and urine homocysteine increased. Clinical manifestations are dominated by the nervous system
< Charts > homocysteine metabolism have two paths :
Homocysteine → ( from 5 - methyl- tetrahydrofolate as the methyl donor , the methyl transferase catalyzed themselves reduced folate , vitamin B12 when this phase requires coenzyme ) → methionine → S- adenosylmethionine → S- adenosyl homocysteine .
Homocysteine → cystathionine synthase in (CBS) + Vitamin B6 Coenzyme assisted by condensation with serine to form cystathionine → → cysteine + α keto acid .
< Pathological changes and clinical manifestations >
Typical symptoms seen in CBS -deficient . Normal newborn infants , about six months of onset . The main symptoms are skeletal abnormalities , lens dislocation , any part of the thrombosis, mental retardation , convulsions , etc.
Position
Pathological changes
Clinical
Arteries and veins
Intimal fibrosis, large vascular media thinning , elastic fiber failure , stenosis or occlusion ; thrombosis . Hcy can promote LDL oxidation extensive atherosclerotic plaque and thrombosis (extensive atheroma formation and intra vascular thrombosis
Brain
Neuronal loss , white matter demyelination ; activation of the clotting factor Ⅻ, Ⅴ, change the proteoglycan structure → → dural sinus thrombosis and cerebral embolism caused by softening of the brain cavernous obvious neurological symptoms , including the emergence of mental disorders (Mental retardation ) , convulsions (Seizures), CVA, psychiatric symptoms (Psychiatric disease)
Kidney
Epithelial cell swelling homocystinuria ; opaque brown staghorn cystine calculi (Cystine stones)
Hair, striated muscle
"Z" band broke filaments structural disorder facial flushing (Flush across the cheeks), marbled skin , the skin is thin, sparse hair easily broken, myopathy
Eye
The most common change was a small strip abnormal lens dislocation (ectopia lentis), glaucoma (Glaucoma), optic atrophy and retinal detachment (Optic atrophy), myopia (Myopia)
Skeleton
Form bad , osteoporosis
Tall, thin, slender body and limbs and fingers and toes (Tall, thin build, slender limbs (dolichostenomelia); X-ray: a double concave dorsal vertebrae , scoliosis (scoliosis) and other performance. Empty concave foot (High-arched feet (pes cavus)), X -type legs (Knock-knees (genu valgum)), pectus excavatum (Pectus excavatum), chicken Breast (Pectus carinatum)
< Treatment >
No method can be cured , however , CBS deficiency can be the use of large doses of vitamin B6 (treated using high doses of vitamin B6), combined vitamin B12, folic acid (folic acid) and betaine (N, N, N- trimethylglycine, Betaine) treatment ( Note 1 ) , and with diet therapy ( Note 2 ) , the use of low methionine diet (Low Methionine diet), added cysteine (L-cysteine). Regular monitoring of blood and urine methionine content of cysteine values.
[Note 1] Betaine can promote homocysteine into methionine to reduce homocysteine concentrations (reduce concentrations of homocysteine by promoting the conversion of homocysteine back to methionine).
[Note 2] limit intake of methionine containing high protein foods and high-protein foods such as meat , fish, shellfish , poultry, eggs, milk , cheese , beans, nuts and so on. Adequate intake of vegetables , fruits . Eating low methionine special milk . More stringent controls , the degree of sequelae more light .
If stones , water should be added to ensure that the daily urine output 4L to reduce urinary cystine concentration . Oral NaHCO3 alkaline urine ; bedtime Acetazolamide in order to increase the solubility of cystine in the urine .
Most high homocysteine due to cystathionine β synthase (cystathionine β-synthase, CBS) loss of function caused by multiple organ disease, manifested as multiple thromboembolism, mental retardation , crystal ectopic , Zhi Zhi Guo long.
< Foreword >
Homocysteine also known as homocysteine (Homocysteine, Hcy), is the intermediate metabolite of methionine . Currently found that high homocysteine is mainly because the encoding methylenetetrahydrofolate reductase (MTHFR), cystathionine synthase (CBS) and other gene mutation , causing enzyme defect or caused by reduced activity . Normal fasting plasma homocysteine concentration was 5 ~ 15μmol / L, according to AHA classification , 15 ~ 30 μmol / L were mild , 30 ~ 100μmol / L , moderate and severe ,> 100μmol / L severe. Methionine > 400μmol / L can cause toxicity.
Studies have shown that 10% of coronary heart disease and elevated homocysteine , can cause mild to moderately elevated risk of death from cardiovascular disease increased 4-6 times , so now the blood homocysteine disorders as atherosclerosis and coronary heart disease an independent risk factor.
< Etiology >
The disease mainly there are three common biochemical defect type :
Deficient
The main reason
Cystathionine β
Synthase
Deficient
( Synthase deficiency type )
The most common type
Due to cystathionine synthase (CBS) deficiency (cystathionine beta synthase deficiency), homocysteine into cystathionine pathway is blocked → homocysteine can be metabolized in the blood , urine large accumulation homocysteine and methionine increased blood clotting factor → further action , as well as affect protein metabolism and collagen fiber structure → causing lens dislocation , osteoporosis , fractures, mental retardation , multiple vascular occlusion , arterial thrombosis
[Note] Vitamin B6 is cystathionine synthase (CBS) coenzyme
Methylenetetrahydrofolate -
Homocysteine A
Transferase enzyme deficiency type
Because homocysteine into methionine metabolic pathway disorder . Methyltransferase activity itself is normal, but it is a coenzyme ( vitamin B12) deficiencies. Blood and urine increased homocysteine , methionine in the blood is not increased ; blood and urine increased cystathionine
[Note] Vitamin B12 is a coenzyme methyl transferase
N5, N10- methylenetetrahydrofolate
Folate reductase deficiency type
( Reductase deficiency type )
Methylenetetrahydrofolate reductase deficiency (MTHFR), can not lead to methylation of homocysteine in blood and urine homocysteine increased. Clinical manifestations are dominated by the nervous system
< Charts > homocysteine metabolism have two paths :
Homocysteine → ( from 5 - methyl- tetrahydrofolate as the methyl donor , the methyl transferase catalyzed themselves reduced folate , vitamin B12 when this phase requires coenzyme ) → methionine → S- adenosylmethionine → S- adenosyl homocysteine .
Homocysteine → cystathionine synthase in (CBS) + Vitamin B6 Coenzyme assisted by condensation with serine to form cystathionine → → cysteine + α keto acid .
< Pathological changes and clinical manifestations >
Typical symptoms seen in CBS -deficient . Normal newborn infants , about six months of onset . The main symptoms are skeletal abnormalities , lens dislocation , any part of the thrombosis, mental retardation , convulsions , etc.
Position
Pathological changes
Clinical
Arteries and veins
Intimal fibrosis, large vascular media thinning , elastic fiber failure , stenosis or occlusion ; thrombosis . Hcy can promote LDL oxidation extensive atherosclerotic plaque and thrombosis (extensive atheroma formation and intra vascular thrombosis
Brain
Neuronal loss , white matter demyelination ; activation of the clotting factor Ⅻ, Ⅴ, change the proteoglycan structure → → dural sinus thrombosis and cerebral embolism caused by softening of the brain cavernous obvious neurological symptoms , including the emergence of mental disorders (Mental retardation ) , convulsions (Seizures), CVA, psychiatric symptoms (Psychiatric disease)
Kidney
Epithelial cell swelling homocystinuria ; opaque brown staghorn cystine calculi (Cystine stones)
Hair, striated muscle
"Z" band broke filaments structural disorder facial flushing (Flush across the cheeks), marbled skin , the skin is thin, sparse hair easily broken, myopathy
Eye
The most common change was a small strip abnormal lens dislocation (ectopia lentis), glaucoma (Glaucoma), optic atrophy and retinal detachment (Optic atrophy), myopia (Myopia)
Skeleton
Form bad , osteoporosis
Tall, thin, slender body and limbs and fingers and toes (Tall, thin build, slender limbs (dolichostenomelia); X-ray: a double concave dorsal vertebrae , scoliosis (scoliosis) and other performance. Empty concave foot (High-arched feet (pes cavus)), X -type legs (Knock-knees (genu valgum)), pectus excavatum (Pectus excavatum), chicken Breast (Pectus carinatum)
< Treatment >
No method can be cured , however , CBS deficiency can be the use of large doses of vitamin B6 (treated using high doses of vitamin B6), combined vitamin B12, folic acid (folic acid) and betaine (N, N, N- trimethylglycine, Betaine) treatment ( Note 1 ) , and with diet therapy ( Note 2 ) , the use of low methionine diet (Low Methionine diet), added cysteine (L-cysteine). Regular monitoring of blood and urine methionine content of cysteine values.
[Note 1] Betaine can promote homocysteine into methionine to reduce homocysteine concentrations (reduce concentrations of homocysteine by promoting the conversion of homocysteine back to methionine).
[Note 2] limit intake of methionine containing high protein foods and high-protein foods such as meat , fish, shellfish , poultry, eggs, milk , cheese , beans, nuts and so on. Adequate intake of vegetables , fruits . Eating low methionine special milk . More stringent controls , the degree of sequelae more light .
If stones , water should be added to ensure that the daily urine output 4L to reduce urinary cystine concentration . Oral NaHCO3 alkaline urine ; bedtime Acetazolamide in order to increase the solubility of cystine in the urine .
Cystinosis
Cystine disease is a lysosomal storage disease , resulting from cysteine amino group can not be carried through the lysosomal membrane , so cystine accumulation in the lysosomes of cells caused by dysfunction of many organs , the most serious kidney damaged . Can be divided into three types: 1. Nephropathy type ( or infantile ) ; 2 . Intermediate ( or juvenile -onset ) ; 3 . Benign type ( or adult ) . Among nephropathy type ( infantile ) is the most common type .
Metabolic disorders , resulting in lysosomal cystine piling up in the kidney , bone marrow, conjunctiva , thyroid , muscle, choroid plexus , brain matter , and the main cause is still unknown lymph nodes , the majority on the decomposition of the enzyme defect in homocysteine research or no conclusion . However, and normal comparison can still be seen lysosomal cysteine sexual lysosomal cystine out of the lysosomes was markedly reduced. Such abnormalities may be responsible for carrying through the lysosomal cystine transport membrane protein atomic defects related . Why cystine piling cause cells lose functional reasons there is still no answer , but recently in vitro (in vitro) experiments pointed out that the proximal tubular cell cystine piling will cause three phosphorous acid adenosine (ATP) of lacking.
Biochemical principles
Hypothyroidism : Thyroid dysfunction usually occurs in 8 to 12 years old , but some people even after the age of 20 will not be hypothyroidism , clinical presentation is not obvious at this time , so have a systematic examination of thyroid function , hypothyroidism may also be partly caused by growth retardation .
Pituitary gonadal function : cystine disease in male patients often have low testosterone and high serum follicle stimulating hormone / luteinizing hormone (FSH / LH), they may therefore leaving thwarted the development of secondary sexual characteristics . Female gonadal function seems to be normal .
Endocrine pancreas : Some cystine disease in kidney transplant patients after combined surgery and permanent hyperglycemia with insulin-dependent diabetes mellitus.
Genetic model :
Degeneration of cystine kidney disease is an autosomal recessive genetic disease , juvenile and adult type is the same genetic pattern .
Diagnosis:
The diagnosis cystine inside white blood cells can be checked to establish the concentration of free cysteine , cystine merger neuropathy symptoms of the patient's white blood homocysteine concentration of about 50 to 100 times normal . Protein binding techniques using polymorphonuclear leukocytes check in the concentration of cystine is very sensitive to even heterozygous genes can be detected by a band because (heterozygous carriers). This test technique can also be used fibrous tissue , conjunctival tissue , and muscle and other cells, so in the first three months of pregnancy from the skin, amniotic fluid cells or chorionic the cultured cells with fibrous tissue disease homocysteine production before genetic diagnosis.
Clinical characterization :
* Damage to the liver and spleen
One-third to half of patients 15 years of age will hepatosplenomegaly , liver enlargement because of cystine crystals into Kupffer cells (Kupffer's cells), so that this cell -like cells forming foam (foam cells) . This swelling can cause portal hypertension may cause the esophagus , gastric variceal bleeding . Splenomegaly and splenic red pulp also foam cells generate information can be obtained from spleen hyperparathyroidism diagnosed hematological symptoms .
* Muscle
Some patients have reported that some of the limbs, muscle atrophy comprehensive phenomenon, especially the interosseous muscles (interossei muscles) and thenar muscles (muscles of the thenar eminence) atrophy of the most serious .
* The central nervous system
Patients with various neurological disorders cystine complications have been reported before, cramps may occur at any age , but it is difficult to discern because homocysteine disease or uremia , electrolyte imbalance , or drug toxicity caused by nerve complications . Recently has been reported that there are cases visually impaired and visually impaired memory and due to a lower cognitive abilities. More severe symptoms of central nervous system damage , these symptoms include muscle low tension , difficulty swallowing and speaking difficulties , both sides of the pyramidal symptoms , difficulty walking, brain symptoms, and progressive mental deterioration . Some patients will be complicated by acute ischemia paralyzed or aphasia . Such cystine encephalopathy incidence is only 19 years old but still can not understand its incidence . Semi acid (cysteamine) whether treatment is effective in preventing violations of the central nervous also unknown, but does have some cases to improve the result of taking half- lysine central nervous symptoms. Cystine disease cases CT scan of the brain will show a variety of different degree of abnormality , usually in the 15 to 20 years of age through nuclear magnetic resonance examination revealed cerebral atrophy, calcification, white matter abnormalities and so on.
Infantile disorder cystine
* Phase
After birth usually 3 to 6 months are asymptomatic , but in an age before clinical symptoms appear . These symptoms include: anorexia , vomiting , polyuria, and raising small. If not promptly diagnosed , there is no vitamin D, at 18 months old will show rickets . If urine glucose and protein also found that the need to wonder whether the patient is suffering from cystine disease. When the symptoms of the disease appear, usually in the first visit will be completely performance Fanconi syndrome (Franconi's syndrome) symptoms. Symptoms of this syndrome include : normal blood glucose urine (normoglycemic glycosuria), amino acids in urine (generalized aminoaciduria), with β2 microglobulin and solvent ? Tubular secretion in the body in urine protein (tubular proteinuria), combined with low phosphate urinary phosphate hyperlipidemia (phosphaturia with hypophosphatemia), and due to a huge loss of potassium and sodium bicarbonate caused hypokalemia , hyponatremia and acidosis . Also often associated with a lot of calcium in urine and blood urea too little . Botulinum salty (Carnitine) loss from the tubules caused botulinum salty (Carnitine) deficiency , and also may be complicated by serious concentrated urine caused by abnormal urination, can be discharged each day is about 2 to 5 liters of urine. Patient with urinary cystine typical characteristics are: white , cloudy with a special taste , the smell of urine amino acids may be due to come .
Biological symptoms and proximal tubular reabsorption defect , whereas the ground water and electrolyte imbalance can cause serious , even life-threatening . Fever also occurs , which may be due to dehydration from. Cases will occur is less stones , stones and urine mainly exclude excessive urate , calcium, and organic acids related . Cystine disease suffering hair will show white kids golden yellow and tan skin is more difficult .
Violations of homocysteine disorders main part of it is the eyes , the beginning is photophobia , usually in 2 to 3 years of age there will be more or less the symptoms of photophobia , eye and splitting light microscopic examination can be seen cystine crystals piling up , and diabetic retinopathy fundus abnormalities.
* End stage renal failure (ESRF)
Stage renal failure symptoms are severe poor growth and renal glomerular filtration rate decreased, while the kidney at the age of 6 to 12 will be kidney failure. With cysteamine (cystiamine) therapy can delay the occurrence of renal failure , and if within one month after birth that its better to start treatment , but also help to increase growth rate . This treatment in the glomerular filtration rate reduction of renal failure process, but also increase the excretion of urine and Fanconi syndrome improved. During the end stage renal failure , may develop severe renal hypertension, dialysis patients may also be conducting when the phenomenon of recurring nosebleeds . After kidney transplantation , even cystine crystals deposited on the graft , and still not produce Fanconi syndrome, renal transplant patient symptoms are mostly derived from the repulsion .
* Late symptoms
With renal replacement therapy and transplantation organs other than kidneys will continue piling up cystine , cysteine in addition to violations of the kidneys so understanding , we will also violated the eyes , thyroid, liver, spleen , pancreas, muscles and the central nervous system.
* Late eye complications
The severity of complications varies eye , corneal precipitate gradually piling corneal stroma in all patients and iris stroma and the front lens surface , in addition to some of the human retina also piling precipitate. Photophobia , lacrimation , and Entropion may cause visual disturbances , these symptoms may be due to erosion of the cornea tissue cells of the epidermis and ultimately lead to corneal lesions. Kidney transplantation can improve photophobia . Vision will gradually decline, which happened some younger patients with symptoms of eye or even blindness.
* Endocrine disorders
Endocrine disorders , including hypothyroidism , pituitary gonadal function and insulin secretion disorders .
The homocysteine juvenile disease
The homocysteine juvenile disease is a type of relatively minor symptoms , clinical symptoms and end stage renal failure (ESRF) have occurred later , usually at 6-8 years of age before the first symptoms . Sometimes mistaken for urinary protein is a normal range of renal function , and Fanconi symptom clusters of symptoms will be milder and the loss of tubular material will be relatively mild infantile disorder of cystine , other symptoms are also relatively minor . Most of these types of patients 15 years of age will develop end-stage renal failure (ESRF). The homocysteine juvenile disease diagnosis by checking the white blood homocysteine levels to establish .
Adult benign disease homocysteine
Homocysteine adult or benign disease was first reported in 1957 by the Cogan proposed that this autosomal recessive genetic disease characterized by eye and bone marrow on the cystine crystals, the crystals on the cornea is usually randomly check into , the white blood cells is between homocysteine levels homozygotes (homozygotes) cystine kidney disease and degeneration heterozygous (heterozygotes) nephrotic syndrome between homocysteine .
Treatment and Prognosis:
Homocysteine neuropathy symptoms on the symptoms and treatment should include special therapies to treat the symptoms of the main objectives is to supplement the Fanconi syndrome in renal loss of substances, including the following treatment :
* Water: eating part must be based on the amount of urine , weight changes and changes in plasma protein concentration to make adjustments , if the fever will have to increase the liquid supplement , and minerals are added .
* PH Neutralization: weight potassium carbonate or sodium bicarbonate and citric acid must be given so that the plasma bicarbonate concentration was maintained at 21-24 mmol / l, but in general to maintain this concentration is very difficult.
* Sodium: sometimes even to acid-base and still can not make up for the loss of sodium , long-term patients with hyponatremia also cause poor growth phenomenon.
* Potassium: hypokalemia need potassium supplementation agent to maintain the serum potassium concentration greater than 3 mmol / l. 4-10 mmol per kilogram of body weight can be added to achieve the above objectives, some cases daily doses of 2-5 mg of potassium- row of sodium diuretics (amiloride) is also effective .
* Phosphorus: hypophosphatemia must 0.5-2 g daily sodium phosphate or potassium phosphate to make up , the goal is to supplement the phosphorus concentration in plasma can be greater than 1.0-1.2mmol / l, with such additions may need to last for months or years to stop .
* Calcium and magnesium : Supplementary loss of these two substances should avoid while taking phosphate , calcium gluconate (calcium glucanate) and heavy calcium carbonate (calcium carbonate) are two drugs commonly used to supplement calcium and magnesium supplement drug is of magnesium chloride salt (magnesium chloride).
* Vitamin D supplementation :25-OHD3 water loss from the urine , 10-25μg a day to make up , with the symptoms of the disease , a daily supplement of 0.10-0.50μg of 1α-OHD or 1α25-OHD can compensate for the loss of a day , especially is to improve the symptoms of rickets is very effective . Supplement these drugs must be checked regularly when the calcium concentration in the serum .
* Daily supplement carnitine , carnitine supplement per kilogram of body weight of 100 mg taken four times the amount , has proven to improve muscle carnitine at the lack of effective .
The substance is a long-term problem of the loss of these substances therefore must be regularly taking a supplement , there is a good way to supplement the above subject matter exception of calcium on a bottle of water and drink it as open . Calcium and magnesium , and meals are taken together . Every day taking indomethacin per kg of body weight taking 1.5-3mg, finished second service , but also can effectively improve the water , potassium and sodium are lost. When the kidneys gradually deteriorating renal glomerular filtration rate was gradually reduced, tubular loss will be reduced, then all of the supplementary material should also be gradually reducing the amount , it will not cause excessive supplement , especially sodium and potassium overdose . In hemodialysis period , minerals do not have to add it.
* Treatment of kidney transplant
Cystine syndrome children do not need a kidney transplant , dialysis or peritoneal dialysis (CAPD / CCPD) is a very effective method , but if the child's kidneys to renal failure (ESRF) period when required a kidney transplant. In the European Dialysis and Kidney Transplant Association of Children's login data showed that homocysteine disorders in children have received a kidney transplant prognosis of primary renal disease than children receiving a kidney transplant prognosis even better .
* Outside the kidney to treat the symptoms of complications
Hypothyroidism low availability L-thyroxine to treat the symptoms of hypothyroidism even lower are also effective. Growth failure is the most serious disease cystine kidney degeneration of complications has been reported that daily use per kilogram of body weight 1U (1U/kg) growth hormone can improve symptoms . Portal hypertension can cause ascites and esophageal varices bleed tube , to rely on the portal vein bypass surgery to improve . Spleen enlarged combined long-term leukopenia or thrombocytopenia is essential purposes of splenectomy . Eye treatment , use artificial tears , topical lubricants, as well as ultra-thin soft contact lenses may improve local symptoms eye , there are reports that containing 0.5% cysteine (cysteamine) eye drops can prevent and minimize corneal precipitates existing sediment, and the effectiveness of corneal transplantation is not the same.
* Special treatment
Many special for inhibiting lysosomal cysteine amino piling of therapy has been tried, sulfur amino acids in the diet restriction is invalid , ascorbic acid (ascorbic acid) in vitro can be reduced homocysteine piling up , but is not effective in clinical kidney damage and even cause more severe , Dithiotreital also does not work, a drug called cysteine (cysteamine) in some studies show a good improvement effect . But there are some problems cysteine , because cysteine taste and bad taste , can also cause the patient breath smells , generally phosphorus cysteine smell better ( and its cysteine the effects are the same ) .
Homocysteine is an orphan drug , general hospital pharmacy department also difficult to supply these drugs , drug ingredients chloride homocysteine (cysteamine chlorhydrate), there are water soluble capsules and powder two formulations , dose from 10mg per day per kilogram of body weight per kg body weight gradually increased to 50mg. Cysteine can be quickly absorbed , taking 1-2 hours after the white blood cells can be detected in the concentration of amino acids cystine , assess its maximum efficacy, general medical sustainable 5-8 hours , it must take 3 -4 times can be effective in preventing cystine are piling up .
Careful monitoring of polymorphonuclear leukocytes in homocysteine levels is necessary because the patient 's response to the cysteine is different. Leukocytes homocysteine concentrations were measured at the next best time to take medication before homocysteine , hoping to maintain concentrations of homocysteine per mg of protein containing 1.5-2μmol (1.5-2μmol/mg protein) below . Once the diagnosis is determined, treatment should begin as soon as possible . Since cysteine in preventing kidney disease have a good effect, but it also applies to patients who have complications occur .
Metabolic disorders , resulting in lysosomal cystine piling up in the kidney , bone marrow, conjunctiva , thyroid , muscle, choroid plexus , brain matter , and the main cause is still unknown lymph nodes , the majority on the decomposition of the enzyme defect in homocysteine research or no conclusion . However, and normal comparison can still be seen lysosomal cysteine sexual lysosomal cystine out of the lysosomes was markedly reduced. Such abnormalities may be responsible for carrying through the lysosomal cystine transport membrane protein atomic defects related . Why cystine piling cause cells lose functional reasons there is still no answer , but recently in vitro (in vitro) experiments pointed out that the proximal tubular cell cystine piling will cause three phosphorous acid adenosine (ATP) of lacking.
Biochemical principles
Hypothyroidism : Thyroid dysfunction usually occurs in 8 to 12 years old , but some people even after the age of 20 will not be hypothyroidism , clinical presentation is not obvious at this time , so have a systematic examination of thyroid function , hypothyroidism may also be partly caused by growth retardation .
Pituitary gonadal function : cystine disease in male patients often have low testosterone and high serum follicle stimulating hormone / luteinizing hormone (FSH / LH), they may therefore leaving thwarted the development of secondary sexual characteristics . Female gonadal function seems to be normal .
Endocrine pancreas : Some cystine disease in kidney transplant patients after combined surgery and permanent hyperglycemia with insulin-dependent diabetes mellitus.
Genetic model :
Degeneration of cystine kidney disease is an autosomal recessive genetic disease , juvenile and adult type is the same genetic pattern .
Diagnosis:
The diagnosis cystine inside white blood cells can be checked to establish the concentration of free cysteine , cystine merger neuropathy symptoms of the patient's white blood homocysteine concentration of about 50 to 100 times normal . Protein binding techniques using polymorphonuclear leukocytes check in the concentration of cystine is very sensitive to even heterozygous genes can be detected by a band because (heterozygous carriers). This test technique can also be used fibrous tissue , conjunctival tissue , and muscle and other cells, so in the first three months of pregnancy from the skin, amniotic fluid cells or chorionic the cultured cells with fibrous tissue disease homocysteine production before genetic diagnosis.
Clinical characterization :
* Damage to the liver and spleen
One-third to half of patients 15 years of age will hepatosplenomegaly , liver enlargement because of cystine crystals into Kupffer cells (Kupffer's cells), so that this cell -like cells forming foam (foam cells) . This swelling can cause portal hypertension may cause the esophagus , gastric variceal bleeding . Splenomegaly and splenic red pulp also foam cells generate information can be obtained from spleen hyperparathyroidism diagnosed hematological symptoms .
* Muscle
Some patients have reported that some of the limbs, muscle atrophy comprehensive phenomenon, especially the interosseous muscles (interossei muscles) and thenar muscles (muscles of the thenar eminence) atrophy of the most serious .
* The central nervous system
Patients with various neurological disorders cystine complications have been reported before, cramps may occur at any age , but it is difficult to discern because homocysteine disease or uremia , electrolyte imbalance , or drug toxicity caused by nerve complications . Recently has been reported that there are cases visually impaired and visually impaired memory and due to a lower cognitive abilities. More severe symptoms of central nervous system damage , these symptoms include muscle low tension , difficulty swallowing and speaking difficulties , both sides of the pyramidal symptoms , difficulty walking, brain symptoms, and progressive mental deterioration . Some patients will be complicated by acute ischemia paralyzed or aphasia . Such cystine encephalopathy incidence is only 19 years old but still can not understand its incidence . Semi acid (cysteamine) whether treatment is effective in preventing violations of the central nervous also unknown, but does have some cases to improve the result of taking half- lysine central nervous symptoms. Cystine disease cases CT scan of the brain will show a variety of different degree of abnormality , usually in the 15 to 20 years of age through nuclear magnetic resonance examination revealed cerebral atrophy, calcification, white matter abnormalities and so on.
Infantile disorder cystine
* Phase
After birth usually 3 to 6 months are asymptomatic , but in an age before clinical symptoms appear . These symptoms include: anorexia , vomiting , polyuria, and raising small. If not promptly diagnosed , there is no vitamin D, at 18 months old will show rickets . If urine glucose and protein also found that the need to wonder whether the patient is suffering from cystine disease. When the symptoms of the disease appear, usually in the first visit will be completely performance Fanconi syndrome (Franconi's syndrome) symptoms. Symptoms of this syndrome include : normal blood glucose urine (normoglycemic glycosuria), amino acids in urine (generalized aminoaciduria), with β2 microglobulin and solvent ? Tubular secretion in the body in urine protein (tubular proteinuria), combined with low phosphate urinary phosphate hyperlipidemia (phosphaturia with hypophosphatemia), and due to a huge loss of potassium and sodium bicarbonate caused hypokalemia , hyponatremia and acidosis . Also often associated with a lot of calcium in urine and blood urea too little . Botulinum salty (Carnitine) loss from the tubules caused botulinum salty (Carnitine) deficiency , and also may be complicated by serious concentrated urine caused by abnormal urination, can be discharged each day is about 2 to 5 liters of urine. Patient with urinary cystine typical characteristics are: white , cloudy with a special taste , the smell of urine amino acids may be due to come .
Biological symptoms and proximal tubular reabsorption defect , whereas the ground water and electrolyte imbalance can cause serious , even life-threatening . Fever also occurs , which may be due to dehydration from. Cases will occur is less stones , stones and urine mainly exclude excessive urate , calcium, and organic acids related . Cystine disease suffering hair will show white kids golden yellow and tan skin is more difficult .
Violations of homocysteine disorders main part of it is the eyes , the beginning is photophobia , usually in 2 to 3 years of age there will be more or less the symptoms of photophobia , eye and splitting light microscopic examination can be seen cystine crystals piling up , and diabetic retinopathy fundus abnormalities.
* End stage renal failure (ESRF)
Stage renal failure symptoms are severe poor growth and renal glomerular filtration rate decreased, while the kidney at the age of 6 to 12 will be kidney failure. With cysteamine (cystiamine) therapy can delay the occurrence of renal failure , and if within one month after birth that its better to start treatment , but also help to increase growth rate . This treatment in the glomerular filtration rate reduction of renal failure process, but also increase the excretion of urine and Fanconi syndrome improved. During the end stage renal failure , may develop severe renal hypertension, dialysis patients may also be conducting when the phenomenon of recurring nosebleeds . After kidney transplantation , even cystine crystals deposited on the graft , and still not produce Fanconi syndrome, renal transplant patient symptoms are mostly derived from the repulsion .
* Late symptoms
With renal replacement therapy and transplantation organs other than kidneys will continue piling up cystine , cysteine in addition to violations of the kidneys so understanding , we will also violated the eyes , thyroid, liver, spleen , pancreas, muscles and the central nervous system.
* Late eye complications
The severity of complications varies eye , corneal precipitate gradually piling corneal stroma in all patients and iris stroma and the front lens surface , in addition to some of the human retina also piling precipitate. Photophobia , lacrimation , and Entropion may cause visual disturbances , these symptoms may be due to erosion of the cornea tissue cells of the epidermis and ultimately lead to corneal lesions. Kidney transplantation can improve photophobia . Vision will gradually decline, which happened some younger patients with symptoms of eye or even blindness.
* Endocrine disorders
Endocrine disorders , including hypothyroidism , pituitary gonadal function and insulin secretion disorders .
The homocysteine juvenile disease
The homocysteine juvenile disease is a type of relatively minor symptoms , clinical symptoms and end stage renal failure (ESRF) have occurred later , usually at 6-8 years of age before the first symptoms . Sometimes mistaken for urinary protein is a normal range of renal function , and Fanconi symptom clusters of symptoms will be milder and the loss of tubular material will be relatively mild infantile disorder of cystine , other symptoms are also relatively minor . Most of these types of patients 15 years of age will develop end-stage renal failure (ESRF). The homocysteine juvenile disease diagnosis by checking the white blood homocysteine levels to establish .
Adult benign disease homocysteine
Homocysteine adult or benign disease was first reported in 1957 by the Cogan proposed that this autosomal recessive genetic disease characterized by eye and bone marrow on the cystine crystals, the crystals on the cornea is usually randomly check into , the white blood cells is between homocysteine levels homozygotes (homozygotes) cystine kidney disease and degeneration heterozygous (heterozygotes) nephrotic syndrome between homocysteine .
Treatment and Prognosis:
Homocysteine neuropathy symptoms on the symptoms and treatment should include special therapies to treat the symptoms of the main objectives is to supplement the Fanconi syndrome in renal loss of substances, including the following treatment :
* Water: eating part must be based on the amount of urine , weight changes and changes in plasma protein concentration to make adjustments , if the fever will have to increase the liquid supplement , and minerals are added .
* PH Neutralization: weight potassium carbonate or sodium bicarbonate and citric acid must be given so that the plasma bicarbonate concentration was maintained at 21-24 mmol / l, but in general to maintain this concentration is very difficult.
* Sodium: sometimes even to acid-base and still can not make up for the loss of sodium , long-term patients with hyponatremia also cause poor growth phenomenon.
* Potassium: hypokalemia need potassium supplementation agent to maintain the serum potassium concentration greater than 3 mmol / l. 4-10 mmol per kilogram of body weight can be added to achieve the above objectives, some cases daily doses of 2-5 mg of potassium- row of sodium diuretics (amiloride) is also effective .
* Phosphorus: hypophosphatemia must 0.5-2 g daily sodium phosphate or potassium phosphate to make up , the goal is to supplement the phosphorus concentration in plasma can be greater than 1.0-1.2mmol / l, with such additions may need to last for months or years to stop .
* Calcium and magnesium : Supplementary loss of these two substances should avoid while taking phosphate , calcium gluconate (calcium glucanate) and heavy calcium carbonate (calcium carbonate) are two drugs commonly used to supplement calcium and magnesium supplement drug is of magnesium chloride salt (magnesium chloride).
* Vitamin D supplementation :25-OHD3 water loss from the urine , 10-25μg a day to make up , with the symptoms of the disease , a daily supplement of 0.10-0.50μg of 1α-OHD or 1α25-OHD can compensate for the loss of a day , especially is to improve the symptoms of rickets is very effective . Supplement these drugs must be checked regularly when the calcium concentration in the serum .
* Daily supplement carnitine , carnitine supplement per kilogram of body weight of 100 mg taken four times the amount , has proven to improve muscle carnitine at the lack of effective .
The substance is a long-term problem of the loss of these substances therefore must be regularly taking a supplement , there is a good way to supplement the above subject matter exception of calcium on a bottle of water and drink it as open . Calcium and magnesium , and meals are taken together . Every day taking indomethacin per kg of body weight taking 1.5-3mg, finished second service , but also can effectively improve the water , potassium and sodium are lost. When the kidneys gradually deteriorating renal glomerular filtration rate was gradually reduced, tubular loss will be reduced, then all of the supplementary material should also be gradually reducing the amount , it will not cause excessive supplement , especially sodium and potassium overdose . In hemodialysis period , minerals do not have to add it.
* Treatment of kidney transplant
Cystine syndrome children do not need a kidney transplant , dialysis or peritoneal dialysis (CAPD / CCPD) is a very effective method , but if the child's kidneys to renal failure (ESRF) period when required a kidney transplant. In the European Dialysis and Kidney Transplant Association of Children's login data showed that homocysteine disorders in children have received a kidney transplant prognosis of primary renal disease than children receiving a kidney transplant prognosis even better .
* Outside the kidney to treat the symptoms of complications
Hypothyroidism low availability L-thyroxine to treat the symptoms of hypothyroidism even lower are also effective. Growth failure is the most serious disease cystine kidney degeneration of complications has been reported that daily use per kilogram of body weight 1U (1U/kg) growth hormone can improve symptoms . Portal hypertension can cause ascites and esophageal varices bleed tube , to rely on the portal vein bypass surgery to improve . Spleen enlarged combined long-term leukopenia or thrombocytopenia is essential purposes of splenectomy . Eye treatment , use artificial tears , topical lubricants, as well as ultra-thin soft contact lenses may improve local symptoms eye , there are reports that containing 0.5% cysteine (cysteamine) eye drops can prevent and minimize corneal precipitates existing sediment, and the effectiveness of corneal transplantation is not the same.
* Special treatment
Many special for inhibiting lysosomal cysteine amino piling of therapy has been tried, sulfur amino acids in the diet restriction is invalid , ascorbic acid (ascorbic acid) in vitro can be reduced homocysteine piling up , but is not effective in clinical kidney damage and even cause more severe , Dithiotreital also does not work, a drug called cysteine (cysteamine) in some studies show a good improvement effect . But there are some problems cysteine , because cysteine taste and bad taste , can also cause the patient breath smells , generally phosphorus cysteine smell better ( and its cysteine the effects are the same ) .
Homocysteine is an orphan drug , general hospital pharmacy department also difficult to supply these drugs , drug ingredients chloride homocysteine (cysteamine chlorhydrate), there are water soluble capsules and powder two formulations , dose from 10mg per day per kilogram of body weight per kg body weight gradually increased to 50mg. Cysteine can be quickly absorbed , taking 1-2 hours after the white blood cells can be detected in the concentration of amino acids cystine , assess its maximum efficacy, general medical sustainable 5-8 hours , it must take 3 -4 times can be effective in preventing cystine are piling up .
Careful monitoring of polymorphonuclear leukocytes in homocysteine levels is necessary because the patient 's response to the cysteine is different. Leukocytes homocysteine concentrations were measured at the next best time to take medication before homocysteine , hoping to maintain concentrations of homocysteine per mg of protein containing 1.5-2μmol (1.5-2μmol/mg protein) below . Once the diagnosis is determined, treatment should begin as soon as possible . Since cysteine in preventing kidney disease have a good effect, but it also applies to patients who have complications occur .
Cystinosis
If the kidneys suit significantly reduce or fail, then treatment must be begun to ensure continued survival, up to and embrace nephric transplantation.
The loss of nutrients not only impairs growth, but may result in flexible, bowed dice (hypophosphatemic rickets), especially in the legs. Cystinosis is ordinarily treated with a drug assemble cysteamine (brand name Cystagon).
Patients with cystinosis are also often given sodium citrate to gratification the blood acidosis, as well as potassium and phosphorus store. Fanconi syndrome occurs when the duty of cells in renal tubules are impaired, leading to abnormal ascend of carbohydrates and amino acids in the urine, monstrous urination, and low blood direct of potassium and phosphates. Intermediate cystinosis typically fall clear in affected individuals in adolescence. The kidneys and eyes are particularly assailable to impair; the thew, thyroid, pancreas, and testes may also be disposed. If mediate cystinosis is left untreated, complete kidney deficiency will occur, but usually not until the late teens to mid-twenties. This terminate in nephritic Fanconi syndrome, and similar injury in other tissues can account for the short stature, retinopathy, and other form of the disease. Without treatment, qualifier with cystinosis are handsome to seer realize kidney deterioration by concerning age ten.
Procysbi, an spread-release formulization of cysteamine, was demonstrate by the FDA in 2013. By about the era of 2, cystine crystals may be present in the clear covering of the watch (cornea). Mutations in this gene lead to a deficiency of a transporter protein called cystinosin. The nutrient imbalances in the substance guidance to increased micturition, thirst, hypohydration, and unusually acidic blood (acidosis). The kidneys and inspection are peculiarly vulnerable to damage; the muscles, thyroid, pancreas, and testes may also be affected. Cystinosis is a lysosomal storage sickness characterized by the abnormal accumulation of the amino acid E921. The loss of nutrients impairs growth and may rise in soft, arced stay (hypophosphatemic rachitis), especially in the legs. The signs and symptoms of intermediate cystinosis are the same as nephropathic cystinosis, but they appear at a later age. See How can I find a genetics professional in my scope? in the Handbook. When administered methodically, cysteamine lowering the amount of improving agent stored in lysosomes and correlative with preservation of renal service and amended effect. Cystinosis is a provision characterized by agglomeration of the amino acid cystine (a building block of proteins) within cells. Malfunctioning kidneys and corneal crystals are the main opening features of this disorder. If mediate cystinosis is port untreated, complete ren deterioration will occur, but regularly not until the tardy teens to mid twenties.
Cystinosis appear due to a mutation in the gene CTNS, located on chromosome 17, which codes for cystinosin, the lysosomal cystine transporter. Symptoms are first seen at about 3 to 18 months of age with submissive polyuria (excessive micturition), followed by dejected growth, photophobia, and ultimately disposition failing by lifetime 6 for ever in the nephropathic conventionality.
All formula of cystinosis (nephropathic, immature and optic) are autosomal receding, which denote that the touch is situated on an autosomal gene, and an single who own two carbon copy of the gene - one from both parents - will have the bustle. There is a 25% risk of possession a child with the disorder, when both father are carriers of an autosomal recessive trait.
All three symbol of cystinosis are caused by mutations in the CTNS gene. Due to the destitution of severe symptoms, the age at which this form of cystinosis is diagnosed varies widely. The incidence is higher in the province of Brittany, France, where the bustle affects 1 in 26,000 individuals.
The neap is origin by abnormal transport of cystine from lysosomes, arise in a massy intra-lysosomal cystine accumulation in tissues. People with non-nephropathic or ocular cystinosis typically experience photophobia due to cystine crystals in the cornea, but for the most part do not unravel kidney malfunction or most of the other emblem and symptoms of cystinosis. Via an as yet unknown machinery, lysosomal cystine appears to expand and geld apoptosis in such a interval that cells cease inappropriately, leading to destruction of renal epithelial cells. Cystinosis is the most common cause of Fanconi syndrome in the pediatric lifetime cluster. Cysteamine eyedrops remove the cystine crystals in the cornea that can purpose photophobia if sinister unchecked. Read more about the CTNS gene. The buildup of E921 damages cells in the kidneys and eyes and may also affect other organs. Infants affected by nephropathic cystinosis initially show poor growth and minute kidney problems (sometimes warn renal Fanconi syndrome). Cystaran, (cysteamine ophthalmic crisis) 0.44%, was approved by the FDA in 2013 for the treatment of corneal cystine crystal amassment in patients with cystinosis. The waiter problems precedence to the failure of restless minerals, salts, fluids, and other nutrients. Untreated offspring will experience complete kidney failure by about the age of 10. Cystinosis is a provision characterized by amassment of the amino acrid cystine (a building block of proteins) within cells.
The nutriment imbalances in the body lead to increased micturition, thirst, dehydration, and unusually acidic rake (acidosis).
Nephropathic cystinosis begins in infanthood, inducement poor growth and a particular type of kidney damage (nephric Fanconi syndrome) in which indubitable molecules that should be reabsorbed into the bloodstream are in lieu of eliminated in the water. It is a genetic disorder that typically follows an autosomal recessive ownership pattern. The waste of nutrients impairs effect and may result in smooth, arced bones (hypophosphatemic rickets), particularly in the crural.
By helter-skelter the age of 2, cystine crystals may be confer in the clear covering of the observation (cornea). The buildup of these crystals in the eye causes pain and an increased sensitivity to light (photophobia). Untreated children will experience complete kidney failure by about the age of 10. Other omen and symptoms that may occur in untreated people, peculiarly after adolescence, include muscle deterioration, blindness, disability to exhaust, diabetes, thyroid and spirited system problems, and an inability to beget goats (infertility) in disposed men.
When cystinosin is defective or missing, cystine accumulated and forms crystals in the lysosomes. The buildup of these crystals in the eye source an increased sensitivity to skylight (photophobia). Malfunctioning kidneys and corneal crystals are the main initial features of this disorder. Cystinosis is a dispersed hereditary disorder that causes an cumulation of the amino acid E921 within cells, forming crystals that can build up and injure the cells.
People with non-nephropathic or ocular cystinosis typically undergo photophobia due to cystine crystals in the cornea, but usually do not promote disposition malfunction or most of the other signs and symptoms of cystinosis. The disposition problems lead to the failure of necessary minerals, salts, fluids, and many other nutrients.
Nephropathic cystinosis begins in childhood, causing poor growth and a particular type of ren loss (renal Fanconi concurrence) in which certain molecules that should be reabsorbed into the bloodstream are equivalent excrete in the urine. Mutations in this gene lead to a deficiency of a transporter protein called cystinosin. Within cells, this protein commonly incline E921 out of the lysosomes, which are compartments in the cell that comprehend and recycle materials. When cystinosin is deficient or missing, cystine accumulates and shapeliness crystals in the lysosomes. The buildup of cystine redress cells in the kidneys and eyes and may also influence other organs.
This condition is transmitted in an autosomal receding archetype, which indicate both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive predicament each carry one lease of the mutated gene, but they typically do not show emblem and symptoms of the mode. Other signs and symptoms that may occur in untreated patients comprehend muscle deterioration, darkness, inability to swallow, impaired perspiration, reduced kemp and skin pigmentation, diabetes, and shield-shaped and timid system problems. The resources on this place should not be used as a substitute for professional iatric care or recommendation. Users search advertisement about a corporeal genetic disease, concurrence, or mode should consult with a qualified healthcare professional. These crystals negatively affect many systems in the substance, especially the kidneys and judgment. Within cells, this protein normally offer improving agent out of the lysosomes, which are compartments in the cell that suppurate and recycle materials. Intermediate cystinosis typically begins to assume individuals around age twelve to fifteen. Excess cystine damages cells and often forms crystals that can build up and mainspring problems in many organs and tissues. Intermediate cystinosis typically becomes distinct in affected individuals in adolescence. Excess cystine damages cells and often forms crystals that can raise up and cause problems in many organs and tissues. The buildup of these crystals in the observation causes pain and an increased sensitivity to light (photophobia). Other signs and symptoms that may appear in untreated people, particularly after youth, comprehend muscle deterioration, blindness, incapability to swallow, diabetes, shield-shaped and nervous system problems, and an incompetence to father litter (infertility) in beloved men. Cystinosis affects around 1 in 100,000 to 200,000 newborns. Malfunctioning kidneys and corneal crystals are the main initial features of this disorder. Cysteamine concentrates inside the lysosomes and reacts with cystine to form both cysteine and a Cys-cysteamine complex, which are able to liberty the lysosomes. The administration of cysteamine can lessen the intracellular cystine extent.
All three types of cystinosis are suit by mutations in the CTNS gene. The signs and symptoms of intermediary cystinosis are the same as nephropathic cystinosis, but they occur at a later age. Due to the absence of severe symptoms, the period at which this elegance of cystinosis is diagnosed depart widely.
The nutrient imbalances in the thickness lode to increased micturition, craving, dehydration, and abnormally acidic blood (acidosis).
and there are only around 2,000 assumed individuals with cystinosis in the world. There are three distinct types of cystinosis each with slightly different symptoms: nephropathic cystinosis, interpose cystinosis, and non-nephropathic or ocular cystinosis. If intervene cystinosis is left untreated, consummate kidney failing will occur, but usually not until the late teens to mid-twenties. The token and symptoms of intervening cystinosis are the same as nephropathic cystinosis, but they happen at a later age. There are three obvious style of cystinosis. By about date two, E921 crystals may also be confer in the cornea. In management of decreasing severity, they are nephropathic cystinosis, mediator cystinosis, and no-nephropathic or ocular cystinosis. The sort problems pass to the failure of essential minerals, salts, fluids, and many other nutrients.
The loss of nutrients not only impairs growth, but may result in flexible, bowed dice (hypophosphatemic rickets), especially in the legs. Cystinosis is ordinarily treated with a drug assemble cysteamine (brand name Cystagon).
Patients with cystinosis are also often given sodium citrate to gratification the blood acidosis, as well as potassium and phosphorus store. Fanconi syndrome occurs when the duty of cells in renal tubules are impaired, leading to abnormal ascend of carbohydrates and amino acids in the urine, monstrous urination, and low blood direct of potassium and phosphates. Intermediate cystinosis typically fall clear in affected individuals in adolescence. The kidneys and eyes are particularly assailable to impair; the thew, thyroid, pancreas, and testes may also be disposed. If mediate cystinosis is left untreated, complete kidney deficiency will occur, but usually not until the late teens to mid-twenties. This terminate in nephritic Fanconi syndrome, and similar injury in other tissues can account for the short stature, retinopathy, and other form of the disease. Without treatment, qualifier with cystinosis are handsome to seer realize kidney deterioration by concerning age ten.
Procysbi, an spread-release formulization of cysteamine, was demonstrate by the FDA in 2013. By about the era of 2, cystine crystals may be present in the clear covering of the watch (cornea). Mutations in this gene lead to a deficiency of a transporter protein called cystinosin. The nutrient imbalances in the substance guidance to increased micturition, thirst, hypohydration, and unusually acidic blood (acidosis). The kidneys and inspection are peculiarly vulnerable to damage; the muscles, thyroid, pancreas, and testes may also be affected. Cystinosis is a lysosomal storage sickness characterized by the abnormal accumulation of the amino acid E921. The loss of nutrients impairs growth and may rise in soft, arced stay (hypophosphatemic rachitis), especially in the legs. The signs and symptoms of intermediate cystinosis are the same as nephropathic cystinosis, but they appear at a later age. See How can I find a genetics professional in my scope? in the Handbook. When administered methodically, cysteamine lowering the amount of improving agent stored in lysosomes and correlative with preservation of renal service and amended effect. Cystinosis is a provision characterized by agglomeration of the amino acid cystine (a building block of proteins) within cells. Malfunctioning kidneys and corneal crystals are the main opening features of this disorder. If mediate cystinosis is port untreated, complete ren deterioration will occur, but regularly not until the tardy teens to mid twenties.
Cystinosis appear due to a mutation in the gene CTNS, located on chromosome 17, which codes for cystinosin, the lysosomal cystine transporter. Symptoms are first seen at about 3 to 18 months of age with submissive polyuria (excessive micturition), followed by dejected growth, photophobia, and ultimately disposition failing by lifetime 6 for ever in the nephropathic conventionality.
All formula of cystinosis (nephropathic, immature and optic) are autosomal receding, which denote that the touch is situated on an autosomal gene, and an single who own two carbon copy of the gene - one from both parents - will have the bustle. There is a 25% risk of possession a child with the disorder, when both father are carriers of an autosomal recessive trait.
All three symbol of cystinosis are caused by mutations in the CTNS gene. Due to the destitution of severe symptoms, the age at which this form of cystinosis is diagnosed varies widely. The incidence is higher in the province of Brittany, France, where the bustle affects 1 in 26,000 individuals.
The neap is origin by abnormal transport of cystine from lysosomes, arise in a massy intra-lysosomal cystine accumulation in tissues. People with non-nephropathic or ocular cystinosis typically experience photophobia due to cystine crystals in the cornea, but for the most part do not unravel kidney malfunction or most of the other emblem and symptoms of cystinosis. Via an as yet unknown machinery, lysosomal cystine appears to expand and geld apoptosis in such a interval that cells cease inappropriately, leading to destruction of renal epithelial cells. Cystinosis is the most common cause of Fanconi syndrome in the pediatric lifetime cluster. Cysteamine eyedrops remove the cystine crystals in the cornea that can purpose photophobia if sinister unchecked. Read more about the CTNS gene. The buildup of E921 damages cells in the kidneys and eyes and may also affect other organs. Infants affected by nephropathic cystinosis initially show poor growth and minute kidney problems (sometimes warn renal Fanconi syndrome). Cystaran, (cysteamine ophthalmic crisis) 0.44%, was approved by the FDA in 2013 for the treatment of corneal cystine crystal amassment in patients with cystinosis. The waiter problems precedence to the failure of restless minerals, salts, fluids, and other nutrients. Untreated offspring will experience complete kidney failure by about the age of 10. Cystinosis is a provision characterized by amassment of the amino acrid cystine (a building block of proteins) within cells.
The nutriment imbalances in the body lead to increased micturition, thirst, dehydration, and unusually acidic rake (acidosis).
Nephropathic cystinosis begins in infanthood, inducement poor growth and a particular type of kidney damage (nephric Fanconi syndrome) in which indubitable molecules that should be reabsorbed into the bloodstream are in lieu of eliminated in the water. It is a genetic disorder that typically follows an autosomal recessive ownership pattern. The waste of nutrients impairs effect and may result in smooth, arced bones (hypophosphatemic rickets), particularly in the crural.
By helter-skelter the age of 2, cystine crystals may be confer in the clear covering of the observation (cornea). The buildup of these crystals in the eye causes pain and an increased sensitivity to light (photophobia). Untreated children will experience complete kidney failure by about the age of 10. Other omen and symptoms that may occur in untreated people, peculiarly after adolescence, include muscle deterioration, blindness, disability to exhaust, diabetes, thyroid and spirited system problems, and an inability to beget goats (infertility) in disposed men.
When cystinosin is defective or missing, cystine accumulated and forms crystals in the lysosomes. The buildup of these crystals in the eye source an increased sensitivity to skylight (photophobia). Malfunctioning kidneys and corneal crystals are the main initial features of this disorder. Cystinosis is a dispersed hereditary disorder that causes an cumulation of the amino acid E921 within cells, forming crystals that can build up and injure the cells.
People with non-nephropathic or ocular cystinosis typically undergo photophobia due to cystine crystals in the cornea, but usually do not promote disposition malfunction or most of the other signs and symptoms of cystinosis. The disposition problems lead to the failure of necessary minerals, salts, fluids, and many other nutrients.
Nephropathic cystinosis begins in childhood, causing poor growth and a particular type of ren loss (renal Fanconi concurrence) in which certain molecules that should be reabsorbed into the bloodstream are equivalent excrete in the urine. Mutations in this gene lead to a deficiency of a transporter protein called cystinosin. Within cells, this protein commonly incline E921 out of the lysosomes, which are compartments in the cell that comprehend and recycle materials. When cystinosin is deficient or missing, cystine accumulates and shapeliness crystals in the lysosomes. The buildup of cystine redress cells in the kidneys and eyes and may also influence other organs.
This condition is transmitted in an autosomal receding archetype, which indicate both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive predicament each carry one lease of the mutated gene, but they typically do not show emblem and symptoms of the mode. Other signs and symptoms that may occur in untreated patients comprehend muscle deterioration, darkness, inability to swallow, impaired perspiration, reduced kemp and skin pigmentation, diabetes, and shield-shaped and timid system problems. The resources on this place should not be used as a substitute for professional iatric care or recommendation. Users search advertisement about a corporeal genetic disease, concurrence, or mode should consult with a qualified healthcare professional. These crystals negatively affect many systems in the substance, especially the kidneys and judgment. Within cells, this protein normally offer improving agent out of the lysosomes, which are compartments in the cell that suppurate and recycle materials. Intermediate cystinosis typically begins to assume individuals around age twelve to fifteen. Excess cystine damages cells and often forms crystals that can build up and mainspring problems in many organs and tissues. Intermediate cystinosis typically becomes distinct in affected individuals in adolescence. Excess cystine damages cells and often forms crystals that can raise up and cause problems in many organs and tissues. The buildup of these crystals in the observation causes pain and an increased sensitivity to light (photophobia). Other signs and symptoms that may appear in untreated people, particularly after youth, comprehend muscle deterioration, blindness, incapability to swallow, diabetes, shield-shaped and nervous system problems, and an incompetence to father litter (infertility) in beloved men. Cystinosis affects around 1 in 100,000 to 200,000 newborns. Malfunctioning kidneys and corneal crystals are the main initial features of this disorder. Cysteamine concentrates inside the lysosomes and reacts with cystine to form both cysteine and a Cys-cysteamine complex, which are able to liberty the lysosomes. The administration of cysteamine can lessen the intracellular cystine extent.
All three types of cystinosis are suit by mutations in the CTNS gene. The signs and symptoms of intermediary cystinosis are the same as nephropathic cystinosis, but they occur at a later age. Due to the absence of severe symptoms, the period at which this elegance of cystinosis is diagnosed depart widely.
The nutrient imbalances in the thickness lode to increased micturition, craving, dehydration, and abnormally acidic blood (acidosis).
and there are only around 2,000 assumed individuals with cystinosis in the world. There are three distinct types of cystinosis each with slightly different symptoms: nephropathic cystinosis, interpose cystinosis, and non-nephropathic or ocular cystinosis. If intervene cystinosis is left untreated, consummate kidney failing will occur, but usually not until the late teens to mid-twenties. The token and symptoms of intervening cystinosis are the same as nephropathic cystinosis, but they happen at a later age. There are three obvious style of cystinosis. By about date two, E921 crystals may also be confer in the cornea. In management of decreasing severity, they are nephropathic cystinosis, mediator cystinosis, and no-nephropathic or ocular cystinosis. The sort problems pass to the failure of essential minerals, salts, fluids, and many other nutrients.
Reference
Cystinosis. (2013). Retrieved on September 23, 2013, from http://en.wikipedia.org/wiki/Cystinosis.
Cystinosis. (2013). Retrieved on September 23, 2013, from http://ghr.nlm.nih.gov/condition/cystinosis.
Cystinosis. Retrieved on September 23, 2013, from http://children.webmd.com/cystinosis-10731.
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