Heart diseases in India prevalent 28,000 years before Indus Valley Civilisation

January 20, 2009
By Syed Akbar
Hyderabad, Jan 19: Indians have been dying of heart attacks long
before the Indus Valley Civilisation, 5000 years ago.

According to a new research study by the city-based Centre for Cellular
and Molecular Biology, heart diseases in India predate the Indus Valley
Civilisation or the Vedic period by about 28,000 years.

The history of sudden deaths due to heart attacks in Indian populations
traces back to 33,000 years, when people began inhabiting the Indian
sub-continent. Since then heart attacks leading to sudden death have
been a common genetic phenomenon passing on from generation to
generation, making Indians more susceptible to heart problems.

According to Dr Lalji Singh, director of the Centre for Cellular and
Molecular Biology, there was a sudden and unexplainable change
(mutation) in the ancestral populations in India 33,000 years ago and
this is proving to be the "worst luck in the world". The gene in question
provides a protein to bind together the heart muscles. When it becomes
defective, it fails to bind the heart muscles making the heart to work
harder to pump blood. And at one stage in life, heart attack lead to
sudden deaths.

However, indigenous populations in the Andamans and in North-
Eastern States are free of this genetic mutation and hence not
susceptible to cardiac problems from which other Indians suffer.
"The indigenous populations of Andaman and Nicobar inhabited the
islands about 60,000 years ago and since they were isolated, they
escaped from the genetic mutation that occurred in those who came to
the mainland India 30,000 years later," Dr Kumaraswamy Thangaraj,
one of the team members which conducted the study on cardiac
diseases among Indians.

The wayward gene has persisted in the population for generations
because its effects usually develop only after people have had their
children.

According to the CCMB scientists, the lifetime risk of developing heart
failure is roughly one in five for a person aged 40 years. Now that the
defect has been identified, there is a new glimmer of hope. It could be
detected very early during pregnancy. If parents choose, a foetus
having two copies FO the defective gene (homozygous or both from
father and mother) could be aborted after genetic counselling. Carriers
of the defect could be identified at a young age by genetic screening
and advised to adopt a healthier lifestyle.

"Perhaps eventually new drugs could be developed to enhance the
degradation of the abnormal protein and postpone the onset of
symptoms. Cardiac stem cell transplant might be used very effectively
to expand the life span of the individuals who carry the deletion. There
is a market of 60 million people waiting for such therapy," they told
reporters here on Monday.

Two sets of genes are inherited, one from father and one from mother.
If both the sets of genes are defective, children die even before they
celebrate their fifth birthday. If one set is defective, the onset of heart
problems begin after 45 years of age.