Metabolic Analysis of Methylenetetrahydrofolate Reductase Single Nucleotide Polymorphisms (MTHFR 677C

Abstract

Neural tube defects (NTDs)are among the most prevalent and debilitating birth defects with their causes are still unknown, despite mounting evidence that genetic and/or environmental factors may play a role. We aimed to analyze two single nucleotide polymorphisms of methylenetetrahydrofolate reductase (MTHFR) gene, serum folate and vitamin B12 status among a cohort of Egyptian children with NTDs and their mothers. A case-control study has been conducted on 50 Egyptian children with various types of NTDs and their mothers. They were comparable with 50 unrelated healthy, age and sex matched children and their mothers (50) selected as controls. Pediatric and neurosurgical assessments were performed to the included cases. Serum folate and vitamin B12 were measured using ELISA kits. MTHFR 677C<T (rs1801133) and MTHFR1298A<C (rs1801131) were analyzed by restriction fragment length polymorphism using polymerase chain reaction. Lumbosacral meningomyelocele was the most frequent NTDs (50%). Significantly lower serum folate and vitamin B12 among cases and case mothers compared to the control and control mothers (p<0.05 for all). Significantly higher frequencies of both heterozygous mutant (CT) and homozygous mutant (TT) genotypes, and mutant T allele of MTHFR 677C<T among case mothers compared to control mothers (p<0.05 for all), with lack of significant differences of this SNP between pediatric groups. Mutant homozygous (AA) genotype and mutant A allele of MTHFR 1298A<C among control mothers were significantly frequent compared to case mothers (p<0.05 for both), with OR 6.081 and 7.071, [95%CI were 3.071-11.287 and 3.296-15.172, respectively]. Significantly frequent wild homozygous (CC) genotype and normal C allele of MTHFR 1298A<C among children with NTDs compared to the controls (p<0.05 for both), with OR 0.231 and 0.754, [95%CI were 0.095-0.561and 0.432-1.317, respectively].Low serum folate and B12 are frequently common among children with NTDs and their mothers. MTHFR 677C<T in mothers could be considered as genetic risk factors for development of NTDs in their children, while MTHFR1298A<C could be protective genetic factor against NTDs development.