Effects of methionine synthase gene variation in parents on occurence of congenital heart disease in offspring

OBJECTIVE: To investigate the relations of methionine synthase (MS) gene variation in parents with congenital heart disease (CHD) phenotype in offspring. METHODS: We selected 192 CHD patients (93 males and 99 females) and their biological parents (nuclear families) in Liaoning Province as case group, and 104 normal people (60 males and 44 females) and their parents without family history of birth defects as control group. For all subjects the MS gene A2756G locus polymorphism was examined by PCR-RFLP method. The data were analyzed to compare the difference of gene variation between the case parents and controls, and to assess the genetic disequilibrium in the CHD nuclear families. RESULTS: The MS genotype distribution and allele frequencies of the case mothers were not different significantly from those of the control group (P>0.05). The frequency of allele (+) in the case fathers (5.0%) was lower than that of the control (9.1%, P=0.060). The odds ratio (OR) was 0.53 (95% CI: 0.25-1.09). There was no difference in parents' genotype combination between the two groups. The analysis of allele transmission indicated that mutation allele (+) transmission disequilibrium existed in CHD nuclear families. The percentage of allele (+) transmitted from the parents was lower than (-) with being OR 0.26 (95% CI: 0.11-0.60). CONCLUSION: The study shows that the MS gene variation at A2756G locus in parents is associated with occurrence of CHD in offspring, and the mutation allele (+) in parents might be related with the decrease of CHD risk in offspring.