Parental consanguinity increases congenital heart diseases in South India

Background: Congenital heart diseases (CHDs) are the commonest single group of congenital abnormalities with a prevalence ranging from 1.0 to 50.89 per 1000 live births in the world population including India, whereas Mysore has a prevalence of 11.08 per 1000 live births. One of the risk factors for the occurrence of CHDs is parental consanguinity, in particular first-cousin marriage between parents. Aim: The present study examined the role of consanguineous marriages in causing CHDs in Mysore, South India. Subjects and methods: A total of 144 confirmed CHD cases with an age range of I day to 23 years and a control group of 200 families from different localities of Mysore city were considered for the present study. Methods included the establishment of a genetic register and pedigree analysis followed by statistical analysis by logistic regression. Results: The findings revealed that first-cousin marriages (44.68%) and uncle-niece marriages (46.81%) are equally significant in increasing CHDs. The subtypes of CHDs associated with consanguinity were found to be atrial septal defect (ASD) and patent ductus arteriosus (PDA). These findings emphasize the important role played by segregation of recessive genes in the offspring resulting in the causation of CHDs. Conclusion: Therefore, for every incidence of parental consanguinity, the risk (odds) of birth of a child with CHD increases. There is an urgent need to educate the public on the deleterious effects of inbreeding, especially in India, which has high overall consanguinity