RESUMEN
INTRODUCTION: The relationship between chromosomal non‑disjunction leading to aneuploidy and folate metabolism has drawn attention in the recent years. In this study, we examined the polymorphism in the gene encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR), namely, 677 C‑T in women having Down syndrome (DS) children. MATERIALS AND METHODS: The prevalence of these variant genotypes (MTHFR 677 C‑T polymorphism) in women having DS children (case mothers) (n = 110) was compared with controls (n = 111) from Punjab. Genotyping was done using the polymerase chain reaction method followed by restriction fragment length polymorphism. RESULTS: In the present study, 1.8% of case mothers had TT genotype while none of the control mothers showed this genotype. T allele frequency among cases was 0.13 and 0.11 in controls. The Chi‑square value showed a non‑significant difference between cases and controls. CONCLUSION: No association has been observed between 677 C‑T polymorphism and risk of non‑disjunction in case mothers. Detection of polymorphisms in more genes of folate pathway is required to find out the exact cause of non‑disjunction.