Maternal TCN1 (rs526934) G>A Gene Polymorphism and its Association with Congenital Heart Disease (CHD)

Background: Congenital heart diseases (CHDs) represent the most common birth defect, affecting 0.6–9.1 per 1000 live births, and the leading cause of infant deaths worldwide. Genes involved in vitamin B12 metabolism such as TCN1 may affect the balance of folate metabolism and ultimately contribute to the development of CHD through the disrupted folate metabolism pathway.

Methods: A total of 100 pregnant women carrying foetus with congenital heart defects are considered as case group and an equal number of healthy pregnant women carrying healthy foetus devoid of any defects are considered as control group for the present study. Blood samples were collected from all the study subjects. DNA was extracted and genotyping of TCN1 intron 372 G>A (rs526934) polymorphism was carried out using allele specific PCR, followed by agarose gel electrophoresis.

Results: Pregnant women in patient group, with GA genotype has 1.95 times more risk of having foetus with CHD compared to controls. Whereas, GG genotype played a protective role. ‘A’ allele was 2.14 times susceptible towards the disease, while ‘G’ allele showed protective effect.

Conclusion: Understanding the possible underlying genetic factors of vitamin B12 metabolism will lead to an increased understanding of the biological mechanisms underlying the maternal TCN1 gene polymorphism effect on CHD. This helps in early diagnosis, management and provide appropriate therapeutic strategies.