Context:
The GenomeIndia project, which aimed to sequence the whole genomes of 10,000 healthy and unrelated Indians, was launched in January 2020 with funding from the Department of Biotechnology. The project was designed to study genetic diversity across 83 population groups in India, involving a total of 20,000 individuals. The data gathered is expected to significantly contribute to the understanding of genetic mutations, particularly in relation to complex diseases.
- Blood Samples: Blood samples were collected from individuals across 30 tribal and 53 non-tribal populations.
- Sequencing Effort: The sequencing was performed by leading institutions such as the Centre for Brain Research at IISc Bengaluru, Centre for Cellular and Molecular Biology in Hyderabad, and others.
Diverse Sample Collection
- Population Representation: DNA samples were collected from 83 population groups across over 100 distinct geographical locations in India. This approach ensured the inclusion of rare mutations important for understanding complex diseases.
- Sample Size: On average, 159 samples were collected from each non-tribal group, and 75 samples from each tribal group. Special attention was given to obtaining samples from parent-child pairs to uncover de novo mutations (mutations occurring only in the child).
- Exclusions: Two populations were excluded from the final dataset, leaving 9,772 individuals (4,696 males and 5,076 females) for analysis.
Preliminary Findings
- Mutation Discovery: A total of 180 million mutations were identified across the sequenced genomes. Of these, 130 million were in non-sex chromosomes (autosomes), and 50 million were in sex chromosomes (X and Y).
- Non-Coding Regions: A significant portion of these mutations (about 98%) were found in the non-coding regions of the genome, which do not directly code for proteins. Mutations in these regions are crucial for understanding evolutionary history and population-specific genetic traits.
Significance of Endogamous Groups
- Endogamy and Genetic Diversity: The study focused on populations with a history of endogamy (marriage within a specific group). This practice leads to the accumulation of unique genetic variations within these groups, including disease-causing mutations with higher frequencies in certain populations.
- Underrepresentation of Indian Populations: The project addresses the underrepresentation of Indian populations in global genomic studies, which have often been Eurocentric. This study is a step forward in ensuring that India’s genetic diversity is reflected in the global genomic landscape.
Medical Implications
- Precision Medicine: The findings of 130 million genetic variations are expected to drive studies aimed at understanding the role of population-specific genetic mutations in diseases. This could pave the way for precision medicine, where treatments are tailored to the genetic profiles of Indian populations.
- Genomics-Based Diagnostics: The data can facilitate the development of affordable genomics-based diagnostic tools, allowing for early detection, prevention, and management of diseases.
- Public Health Policies: Identifying genetic mutations linked to diseases prevalent in specific endogamous groups can help the government develop targeted public health policies to address these health issues effectively.
The GenomeIndia project is a landmark initiative that contributes significantly to the global understanding of genetic diversity, particularly in underrepresented populations. Its findings have the potential to revolutionize healthcare in India by enabling precision medicine and improving disease prevention and management.
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