Heart disease is the number one killer in the world and India carries more than its share of this burden. Moreover, the problem is set to rise: it is predicted that by 2010 India's population will suffer approximately 60% of the world's heart disease. Today, an international team of 25 scientists from four countries provides a clue to why this is so: 1% of the world's population carries a mutation almost guaranteed to lead to heart problems and most of these come from the Indian subcontinent, where the mutation reaches a frequency of 4%.
Heart disease has many causes, some carried in our genes and others linked to our lifestyle, but all seemingly complex, hard to pin down and incompletely understood. So the new study published in Nature Genetics is striking for the size and simplicity of the effect it reports.
The mutation, a deletion of 25 letters of genetic code from the heart protein gene MYBPC3, is virtually restricted to people from the Indian subcontinent. But there, Caste and Tribe, Hindu, Muslim, Sikh, Christian and others are all united by this affliction.
The mutation was discovered five years ago in two Indian families with cardiomyopathy, but its significance only became apparent after almost 1500 people from many parts of India, some with heart disease and some without, were studied.
Scientists express this genetic risk as an odds ratio, where 1.2 would be a small effect and 2.0 a large one. For the MYBPC3 mutation, the odds ratio is almost off-scale, a staggering 7.0. Carriers usually show few symptoms until middle age, but after that age most are symptomatic and suffer from a range of effects, at worst sudden cardiac death.
Via Science Daily
Now the main point of this post on how this genetic horoscope could be used;
CCMB director Dr Lalji Singh said on Monday that the defect could be detected very early during pregnancy through a pre-natal diagnosis. If parents choose, a foetus having two copies of defective gene (homozygous) could be aborted after genetic counselling.
Via The Times of India
Read posts at Razib's Gene Expression. Especially check the distribution tables.
As a layman Geneticist, I find the consistent 4-7% distribution of this mutation among all the communities across the subcontinent rather intriguing. The difference in haplogroup profile (both mtDNA and Y-chromosome) from Punjab in Pakistan to Tamil Nadu in South India is not trivial. Maybe there is a phenomenon called "Genetic Equilibrium in a geographical area" that I'm not aware of. Since I'm not aware of any such concepts I would say we are all Burushos.