Homocystinuria

1960, Carson and Neill et al in 1962 in Northern Ireland issued the first report on the disease in patients, this case was originally described as an unusual one Marfan syndrome and Marfan syndrome at the age of seven when the kidney accompanied by abnormal situation, in happened when the six-year-old with acute non-inflammatory kidney lesions silk (glomerulonephritis) after recovery and found that there is high blood pressure phenomenon, in this case on the development of mental retardation and is relatively thin, light-colored hair, pale skin, cheeks change red, slender means (arachnodactyly), air-concave foot (pes cavus) and on both sides of the lens dislocation and other symptoms.

Homocystinuria (Homocystinuria) are congenital diseases of amino acid metabolic abnormalities, patients discharged from the urine of a large number of high homocysteine, high blood homocysteine values and methionine values are high. Patients are usually 48-96 hours of birth, you can check out in the urine Homocystinuria existence.

Clinical features

Smart enough ectopic eye lens, heart and vascular disease, blood clots, osteoporosis, thin bones (malformation) clinical symptoms such as ...

The incidence of

Europe and the United States about 1/200000, and Taiwan the incidence of very low, estimated at around 1/500000 or less.

Genetic model

Homocystinuria is an autosomal recessive genetic disorders of amino acid metabolism, both parents are carriers of the recessive (carrier: the Parent with a defective gene, but no clinical symptoms), Patients must be at the same time with two defective genes (from the Parent's to a) be the incidence; parents for the carrier, while at the next pair give birth to the next child for Homocystinuria patients high probability of Tatsu quarter. Probability of disease-free sex.


Treatment

The most common reason is that "CBS enzyme (cystathionine-β-synthase, CBS) cystathionine synthesis of functional lack." While the "CBS lack of enzyme function" can be divided into
1. Of vitamin B6 treatment responders: of "vitamin B6 treatment" of patients, may, by supplementary vitamin B6 so that CBS enzyme function in order to reduce the blood and urine methionine high homocysteine concentration . For newborns and small children, in addition to the "low-methionine diet restrictions" should be given to 25 ~ 100 mg / day of vitamin B6, four weeks; called big babies and adults were given 1 g / day. Such as methionine in the blood for high homocysteine concentrations reduced, would reduce the dose of vitamin B6, because of long-term use will result in peripheral nerve problem. Oral vitamin B12 and vitamin B6 combined betaine (Betaine) supplement, can reduce high homocysteine concentration in blood after a meal, such as methylation process due to consumption of folic acid too much folic acid should also be added.

2. Of vitamin B6 treatment of those who failed to respond: If patients with doses of vitamin B6 is added when no response 1000mg/day should start with low methionine diet for diet control treatment, in order to maintain blood methionine suitable concentration; consumption of low-methionine special formula to supplement the amino acids the body must be in order to maintain normal growth and physiological functions. Also need to add cysteine (L-cysteine) and betaine (Betaine).

Prognosis

Although this disease, we have yet to have special treatment, about 50% of patients treated by vitamin B6 has been improved.