Certain genetic changes in Dravidian women make them more susceptible to breast cancer than their counterparts living in north India.
A team of researchers from the city-based Centre for Cellular and Molecular Biology (CCMB) and the Central Drug Research Institute, Lucknow, have observed that ethnic variations in some genes in Dravidian women are linked to the increased incidence of breast cancer.
“Genetic polymorphisms are created by errors during DNA replication. Polymorphisms exist in all populations in little or large frequency. Therefore, the polymorphism might exist in a population with or without influence on disease susceptibility. If we talk about why these polymorphisms increased breast cancer risk in Dravidian women, we have to stress on differences in the genetic make-up between North Indian and South Indian populations,” Dr Rituraj Konwar of CDRI said.
He said susceptibility to a disease is defined by thousands of polymorphisms (variations) in the entire human genome and not by a single polymorphism. Therefore, it is possible that the genetic risk factors between North and South Indian populations are different. The present study identifies one such factor for South Indian populations.
“South Indian women’s breast cancer risk may partly be explained by TNF (tumour necrosis factor) polymorphisms. North Indian women may have equal risk of breast cancer, but it is possible that the underlying genetic risk factor is different,” Dr Rituraj pointed out.
The study identified one of the several possible genetic risk factors for breast cancer. The risk with this polymorphism seems strong in the South Indian population and it does not seem to affect breast cancer risk in North Indian women.