Screening for methylenetetrahydrofolate reductase C677T and A1298C polymorphisms in Indian patients with idiopathic mental retardation

Abstract

Although genetic, nutritional, and environmental factors have been found to aggravate mental retardation in ∼1% of individuals, no cause is known till date. In this study, two genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR), C677T (rs#1801133) and A1298C (rs#1801131), have been investigated in idiopathic mental retardation (IMR) subjects. Significantly higher frequency of the C677 allele was observed in IMR (n = 155; X2= 5.5; P = 0.019) and moderate IMR (n = 67; X2 = 6.16; P = 0.013) groups as compared to controls (n = 126); for A1298C, no significant difference was noticed. TDT analysis revealed preferential transmission of C677 allele to a small group of mild IMR probands (X2 = 5.545; P= 0.018). Higher frequency of CA haplotype was also noticed in IMR cases as compared to controls (X2 = 6.28; P = 0.012). We infer from the present investigation that these polymorphisms are not contributing to the aetiology of IMR in this population since both case-control and family-based analysis revealed no significant transmission of the mutated allele. © 2008 W. S. Maney and Son Ltd.