Indian researchers for the first time have been successful to identify a gene associated with obesity, quite specific to Indian population.
This is important because identifying the genetic determinants of the body mass index (BMI) will go a long way in better understanding the biological basis of being overweight or obese.
What does this research identify?
Aim of this study was undertaken by a research team led by Dr. Kumarasamy Thangaraj of the Hyderabad-based Centre for Cellular and Molecular Biology (CCMB). The aim of this study was to find a novel lucas in Indian population. In order to do this, they excluded the genes associated with obesity in other populations. Total of 204 non-smoking subjects free from chronic diseases that belonged to different BMI categories including overweight, underweight, normal and obese, were chosen for the study. All the subjects were 20-30 years old.
Nearly one million SNP (single nucleotide polymorphism) markers distributed throughout the genome were analysed. “We found one SNP marker (which is within a gene) of THSD7A was significantly associated with obesity. This gene has not been associated with obesity in the Indian population,” said Dr. Thangaraj. The aim of the study was to find a novel locus in the Indian population. The results were published recently in the International Journal of Obesity.
In order to reconfirm the role, a replication study was conducted which involved 655 people belonging to different BMI categories. The study found a significant association between the marker and obesity.
THSD7A is a neural N-glycoprotein, which promotes angiogenesis. Angiogenesis, in turn, modulates obesity, adipose metabolism and insulin sensitivity. And now, the authors have been able to find a correlation and this information can be used for drug target, early diagnosis of obesity and treatment. Explaining how the gene is linked to obesity, Dr. Thangaraj said: “The gene is present in everyone. But when there is a mutation to the gene, there is a likelihood that the person carrying the mutated gene will end up being obese.”
However, the gene mutation is not found in all obese people and similarly is found in very small number among underweight people. “This is because obesity is a multigenic condition,” he explained. Despite being a multigenic condition, people carrying the mutation can always take measures to keep obesity at bay, he said. There is a possibility that the SNP marker of THSD7A may be associated with obesity in other South Asian population.
The genetic affinity Indians have with other South Asian population has already been well documented in a 2009 study. In the 2009 study, a particular gene mutation in Indians was found to increase the risk of heart failure in people with cardiomyopathy. And this mutation was found to be a risk factor implicated in South Asian people with cardiomyopathy too.