Are heterocygotes for classical homocystinuria at risk of vitamin B(12) and folic acid deficiency?
OBJECTIVES/ DESIGN: Comparative cross-sectional study to assess homocysteine and vitamin status in carriers of CBS gene mutations. METHOD: Subjects included 34 parents (13 males, 21 females, age 27-59 years) of 30 patients with classical homocystinuria due to homozygous cystathionine beta-synthase deficiency. Control subjects were matched for gender and age (13 males, 21 females, age 25-59 years). All subjects were of Qatari origin, had normal liver and renal function tests and had not taken drugs or vitamin supplements prior to the study. The concentrations of homocysteine, folic acid and vitamins B(6) and B(12) in blood were determined after an overnight fast. RESULTS: Heterozygous carriers had significantly increased fasting levels of homocysteine compared to controls (9.1 vs. 8.1mumol/l, P=0.012). Both folic acid (328 vs. 478pmol/l, P=0.002) and vitamin B(12) concentrations (232 vs. 287pmol/l, P=0.013) were reduced whilst there was no significant difference in vitamin B(6) levels b
