. Author manuscript; available in PMC: 2019 Feb 4.

Published in final edited form as: Biomed Pharmacother. 2004 Jan;58(1):47–55. doi: 10.1016/j.biopha.2003.11.005

Table 1.

Biochemical features of homocystinuria

Defect inVitamin B-12 metabolism

Deficiency of N(5,10)-methylenetetrahydrofolate reductase

Selective intestinal malabsorption of B-12

Vitamin B-12 responsive homocystinuria, clb E type

Methylcobalamin deficiency, cbl g type

Vitamin B-12 metabolic defect, type 2

Transcobalamin II deficiency