Which enzyme's abnormal activity is associated with the development of hyperhomocysteinemia, a risk factor for cardiovascular disease?

A Methionine synthase
B Cystathionine beta-synthase
C Methylenetetrahydrofolate reductase (MTHFR) ✓
D Homocysteine methyltransferase

Explanation

Hyperhomocysteinemia is a condition characterized by elevated levels of homocysteine in the blood, which is associated with an increased risk of cardiovascular disease. The enzyme methylenetetrahydrofolate reductase (MTHFR) plays a crucial role in the metabolism of homocysteine, and its abnormal activity can lead to hyperhomocysteinemia.

Source

National Institutes of Health (NIH)
Enzymes in Disease Biochemistry Amino Acid Metabolism Hard MEDICAL Confidence: high