Q. What is Homocystinuria?
Homocystinuria may result from errors of methionine metabolism. This produces defects in the function of cystathionme b synthase or 5-mcthyltctrahydrofolate homocysteine methyltransferase.
The most common form of hornocystinuria is caused by a deficiency of the enzyme cystathionine b synthase. This enzyme is essential for the conversion of homocysteine to cystathionine. Severely impaired enzyme function produces accumulation of plasma homocysteine and methionine and decreased cysteine in cells. Large amounts of homocystine are excreted in the urine.