Endogamy: 6 Things Population Genetics Reveals About a Real Threat to Holistic Health

This article examines endogamy, the practice of marrying within a defined community, as a population genetics phenomenon with documented, measurable consequences for holistic health, distinguishing it precisely from consanguinity, a related but distinct practice of marrying close blood relatives. It reviews the GenomeAsia 100K Project's 2019 finding that several Indian urban population groups show identical-by-descent (IBD) genetic relatedness scores exceeding the Finnish population, long considered medicine's reference case for a genetically isolated founder population. It examines a 2025 CSIR-Centre for Cellular and Molecular Biology study identifying specific, named population-linked conditions, including elevated ankylosing spondylitis incidence linked to the HLA-B27:04 variant in the Reddy community of Andhra Pradesh, and documented differences in metabolism of common drugs including Tacrolimus and Warfarin across Indian population groups. It reviews India's National Family Health Survey data on consanguineous marriage prevalence (9.9% in 2015-2016, rising to 11% in 2019-2021) and the foundational population genetics framework distinguishing recessive disease expression risk from gene pool frequency. The article addresses this subject with explicit care to avoid stigmatizing any specific community, framing endogamy as a population genetics and public health finding rather than a judgment on cultural or marital practice, and concludes with a practical, evidence-based framework centered on genetic counseling and carrier screening rather than prescriptive social change.