Question

Clinical scenario about homocystinuria, which vitamin to be supplemented?

• A. Thiamine
• B. Vitamin B6
• C. Biotin
• D. Pyruvate

Hint:

Vitamin B6 is crucial in managing homocystinuria, as it supports enzyme activity that helps convert homocysteine to cysteine.

Answer 1

The Correct Option is B

In the clinical context of homocystinuria, an understanding of the biochemical pathways is crucial for determining the correct supplementation. Homocystinuria is a genetic disorder characterized by the accumulation of homocysteine in the blood. This condition often results from a deficiency in enzymes involved in the methionine metabolism pathway, particularly cystathionine beta-synthase (CBS). The activity of CBS is dependent on Vitamin B6 (pyridoxine) as a cofactor. Deficiency of this enzyme due to lack of Vitamin B6 will lead to increased levels of homocysteine.

To address this, the correct clinical intervention is to supplement with Vitamin B6, which can enhance the function of cystathionine beta-synthase and thereby facilitate the conversion of homocysteine to cystathionine, reducing its levels in the blood.

Here are the options considered:

• Thiamine – This vitamin is not directly involved in the homocysteine metabolic pathway.
• Vitamin B6 – Correct choice; it acts as a cofactor for cystathionine beta-synthase, aiding in reducing homocysteine levels.
• Biotin – This vitamin plays no role in homocysteine metabolism.
• Pyruvate – Not a vitamin and unrelated to homocysteine metabolism.

Thus, the vitamin to be supplemented in cases of homocystinuria is Vitamin B6.