In India, the tradition of marrying within the kin is known as endogamy. It has been a cultural cornerstone. However, this widespread practice, while deeply rooted in societal norms, is increasingly linked to a surge of inherited health conditions across the country.As per the National Family Health Survey 2005-06, only 10% marriages in India were inter-caste and just 2.1% were interreligious. This highlights how the majority of people practice endogamy. Even, a recent genome mapping study from India's Genome Project confirmed that trend remained strong. All 83 population groups studied showed high levels of endogamy, which has led to population specific genetic mutations and disorders. How Endogamy Contributes to Genetic Disorders?Endogamy has increased the chances of genetic disorders, especially when it overlaps with consanguineous marriages, which means marriages between close relatives. This is much more common in the southern parts of India. Doctors have explained that when both parents carry the same recessive gene mutation, their children have a greater risk of inheriting two copies of the faulty gene. This is also the case with thalassemia cases in India. This can also lead to the manifestation of genetic disorders, even if the parents are asymptomatic carriers. Over generations, such selective mating within communities has further allowed rare mutations to persist and concentrate. This is resulted to what researchers refer to as "population-specific mutations". These can affect various bodily systems, including the heart, joints, and reproductive health. What All Disorders Could Happen?As per the study published in Nature Genetics, Dr Kumaraswamy Thangaraj, Principal Investigator of the Genome India Project, highlighted how these mutations are directly linked to early-onset cardiac issues, particularly in South India. Unlike the North, where cardiac problems come later in life, due to lifestyle issues, people in southern parts of India are affected by population-specific mutations from a younger age. Another health concern that the study highlighted was ankylosing spondylitis, which is a type of arthritis that affects the spine and is more common in genetically homogenous populations. A different study in journal Nature also revealed that consanguineous marriages raise the risk of spontaneous abortions, stillbirths, neonatal and child mortality. Another study published in the Journal of Genetics and Genomics in 2005, titled: Endogamy and high prevalence of deleterious mutations in India: evidence from strong founder events, reads: "Several Indian populations have experienced significant founder events due to strict endogamy. However, the clinical implications of it remain underexplored. Therefore, we perform whole-exome sequencing of 281 individuals from four South Indian populations, characterized by high IBD scores. Our study reveals a high inbreeding rate of 59% across the populations. We identify ∼29.2% of the variants that are exclusively present in a single population and uncover 1284 unreported exonic variants, underscoring the underrepresentation of Indian populations in global databases."What Can Be Done to Avoid This?Experts from time and again have stressed the need for widespread education and awareness as well as genetic counselling. Promoting inter-community marriages can also dilute the concentration of harmful genetic mutations, and also reduce the incidence of hereditary diseases. Doctors can also play a role in advising couples on their health risks, especially if it is with regards to consanguineous marriages and encouraging genetic screening before marriage or conception. The Genome India Project offers hope for future solutions. By mapping the genomes of more than 10,000 individuals, the project aims to identify mutations that are widespread due to endogamy. According to Dr. Thangaraj, these findings could help make diagnostics and treatments more affordable and tailored to India’s unique genetic landscape.