Homocystinuria

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 .