Which enzyme is implicated in the pathogenesis of homocystinuria, a genetic disorder characterized by elevated levels of homocysteine in the blood?

A Cystathionine beta-synthase ✓
B Methionine synthase
C Homocysteine methyltransferase
D Betaine-homocysteine methyltransferase

Explanation

Homocystinuria is caused by a deficiency of the enzyme cystathionine beta-synthase, which catalyzes the conversion of homocysteine to cystathionine. This deficiency leads to an accumulation of homocysteine in the blood, causing a range of clinical symptoms.

Source

OMIM: Homocystinuria
Enzymes in Disease Biochemistry Amino Acid Metabolism Disorders Hard MEDICAL Confidence: high