A groundbreaking genetic study led by Indian scientists, including three researchers from Banaras Hindu University (BHU), has provided new insights into the variations in hair and skin color across populations, explaining why red hair is extremely rare in India. The large-scale study identified an ultra-rare gene variant responsible for red hair in a five-year-old Indian girl, a striking case given that both her parents have normal dark hair and eyes, pointing to a recessive pattern of inheritance.
Role of MC1R Gene
At the center of the research is the melanocortin 1 receptor (MC1R), a protein that regulates melanin production, which determines hair and skin color. While red hair is relatively common in parts of Europe, it is unusual in India. Researchers found that a rare alteration in the MC1R gene led to the child's red hair despite her dark eyes.
Study Details and Findings
The team, led by Kumarasamy Thangaraj, analyzed genetic data from over 10,000 individuals belonging to 91 Indian communities. The analysis led to the identification of 21 new or ultra-rare genetic variants linked to differences in skin and hair pigmentation. The study also found that some genetic variants associated with lighter skin tones were concentrated in specific populations. One such variant, identified in the Ladakh region, was found to be linked to lower melanin levels.
Geographic Distribution of Variants
The research involved 18 authors from 11 institutions across the country and was published this week in Human Genetics and Genomics Advances, a journal of the American Society of Human Genetics. 'The study shows that genetic traits vary sharply across India. Certain variants are more common in northern and northeastern regions, where lighter complexions are more prevalent, and are far less frequent in southern populations,' said Prof Gyaneshwar Chaubey of the Department of Zoology, BHU, a member of the research team. He added that geography, ancestry, and evolution play a major role in shaping physical appearance.
Validation Through Laboratory Techniques
To validate their findings, the researchers used advanced laboratory techniques, including experiments on zebrafish, to observe how the identified genetic changes affect pigmentation. 'The results confirmed that some variants can switch off normal pigment production, leading to features such as lighter skin and red hair,' Prof Chaubey said.
Implications and Future Directions
The study highlights India's vast genetic diversity and its influence on physical traits. It could also help improve understanding of skin-related conditions and support the development of personalized medical approaches in the future.
