Classical Homocystinuria is an autosomal recessive and multisystemic metabolic disorder, caused mainly by mutations in cystathionine beta-synthase (CBS) enzyme involved in methionine metabolism. The frequency of CBS deficiency is variable, being reported in different ranges [1:65,000 to 1:900,000]. The age of onset and severity of symptoms can be extremely variable, ranging from severely affected children to near asymptomatic adults. Two “clinical-biochemical” phenotypes are usually described in CBS deficiency: the so-called B6-responsive homocystinuria and B6-non-responsive homocystinuria. B6-responsive patients have typically - but not always - milder symptons than the non-responsive patients since they have higher residual enzyme levels.
KeywordsHomocystinuria Cystathionine beta-synthase enzyme Psychiatric complications of homocystinuria Pyridoxine treatment for homocystinuria Hyperhomocysteinemia-induced deep vein thrombosis Thrombosis in patient with homocystinuria
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