A recent study conducted by the Institute for Human Genetics, University of California, has unearthed significant genetic differences amongst the populace of different regions on the Indian subcontinent.
The Methodology of the Study
The researchers gathered DNA from approximately 5,000 individuals, predominantly people from India, Pakistan, and Bangladesh. The cohort also included DNA data from several Malay, Tibetan, and other South-Asian communities. They performed Whole-Genome Sequencing to identify each instance where either there was a change in the DNA, an absence of it, or when additional nucleotide base-pairs were present.
Key Findings of the Study – Endogamous Practices and Regional Trends
The study discovered that there is little intermingling between individuals from different communities within the Indian subcontinent. Endogamous practices, such as caste-based, region-based, and close relative marriages, have resulted in distinct genetic patterns at the community level. Ideally, random mating within a population would lead to higher genetic diversity and a lower frequency of variants linked to disorders.
In comparison to a fairly outbred population like Taiwan’s, the South Asian group – including the South-Indian and Pakistani subgroups – exhibited a higher frequency of homozygous genotypes, possibly due to cultural aspects. A Homozygous Genotype arises when an individual carries two copies of the same variant of a gene. The majority of genetic variants associated with significant disorders are recessive and exhibit their effect only when two copies are present.
The South-Indian and Pakistani subgroups manifested a high degree of inbreeding while the Bengali subgroup demonstrated comparably lower inbreeding. Not only did the South Asian group possess a larger number of variants capable of disrupting gene function, but they also had unique variants not found in Europeans.
Risk of Homozygous Variants
The existence of rare homozygous variants amplified the risk of diseases such as cardiovascular diseases, diabetes, cancer, and mental disorders.
Previous Studies on Genetic Diversity
A 2009 study published in Nature Genetics revealed that a small fraction of the Indian population is susceptible to cardiac failure at relatively young ages due to the absence of 25 base-pairs in a gene crucial for the rhythmic beating of the heart. This deletion was unique to the Indian population and wasn’t found elsewhere, except in a few groups in Southeast Asia.
Significance of Studies on Genetic Diversity
Studies have indicated that specific genetic novelties are associated with the health of India’s populace. Understanding these genetic variations can help in devising improved interventions for major health issues. Performing genetic studies domestically can protect susceptible communities from potential exploitation by multinational companies and foreign research establishments.
The Importance of a Detailed Map of the Indian Genome
India’s incredible diversity calls for a detailed genetic map. A comprehensive genetic map can assist in comprehending the genetic basis of health disparities and steer population health interventions. Structures like economical, matrimonial, and geographical aspects add to the need for such a map.