DNA test may help choose the right sport

DNA test may help choose the right sport
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First Published: Sun, Aug 01 2010. 11 35 PM IST
Updated: Sun, Aug 01 2010. 11 35 PM IST
New Delhi: Does a child’s chances of blossoming into an ace sprinter or Olympian marathon runner rest on a sliver of DNA? Sanjeev Chaudhry, the chief executive officer of Super Religare Laboratories Ltd (SRL), one of the country’s largest testing laboratories, is confident it does.
In the little over three months since SRL began offering its “sportsgene” test—where for Rs2,000 lab technicians take a swab of cells from the inside of your cheeks and check for a protein called ACTN3—at least 3,000 children, Chaudhry says, across Delhi, Mumbai and Bangalore have taken the test.
The company was banking on the hype generated by the approaching Commonwealth Games and the recently concluded football World Cup. “These two events contributed to a big interest among parents for getting their children tested. Plus it’s non-invasive and not really expensive,” Chaudhry said in a phone interview.
According to him, the test helped parents make up their minds about investing time and money to “maximize” their child’s sporting ability. “There’s no substitute for training and nutrition, but if a particular gene helps parents nurture their children in the right sport, then it’s a big advantage,” he said.
The gene in question is alpha actinin-3 (ACTN3), which triggers the production of alpha actinin, a protein that boosts a certain class of muscle fibre, called fast-twitch type 2 muscle fibre, which helps muscles generate extra force when stimulated.
According to research studies, approximately three out of five people across racial categories have the ACTN3 gene, which comes in two variants—“R” and “X”. Individuals inherit one copy of a variant from each parent.
While studies by Australian scientists in 2003—that first triggered substantial interest in the innocuous DNA—did suggest that of over 400 elite athletes tested, nearly 72% had at least one “R” variant, the authors themselves warn against choosing a sport based on the presence of a single gene.
The “R” variant helped generate extra muscle force useful in sprints or weightlifting that require rapid bursts of power.
In his blog, Daniel MacArthur, one of the key researchers associated with the study said, “...Parents considering using the test on their children need to be very clear about this: the test provides information about only one small component of a much bigger picture. It’s probably not a great idea to base any important life decisions on such limited information.” He did not respond to a request from Mint for an interview.
MacArthur added that most studies performed so far suggest that ACTN3 explains just 2-3% of the variation in muscle function in the general population. The rest of the variation is determined by a wide range of genetic and environmental factors, most of which (particularly the genetic factors) were very poorly understood.
In 2007, Balraj Mittal, a geneticist at the Sanjay Gandhi Postgraduate Institute of Medical Sciences in Lucknow sampled 125 blood donors in Lucknow and reported in Current Science, a peer-reviewed journal published by the Indian Academy of Sciences, that 52% of them had at least a single “R”, close to the average Asian population of 50% and 56% of European whites.
The scientists say they wanted to downplay the role of genes in determining athletic abilities. “If you compare Olympic medal tallies,” Mittal said, “there’s no comparing Indians with the Europeans, Americans or the Chinese.”
Thus, training, grooming and psychological motivations were the most important factors, he added. Crucially, Mittal and his team didn’t check how the genes were distributed among Indian athletes.
A slew of companies such as the US-based 23andMe Inc. and Australian Genetic Technologies Ltd, among their bouquet of genetic testing services offer to check for ACTN3, according to information on their websites. Emails to the firms went unanswered.
Chaudhry clarifies that SRL’s decision to offer these tests are based on studies specifically conducted in India and that ACTN-3 was one of the “leading factors “ in determining athletic ability.
“We submitted our research conducted in India to two journals of sports medicine and they should be in the public domain in three-six months, “he said. He added that he could share details of the sample population chosen, and other technical details only after the journals published them.
Buoyed by the response to the sports gene test, SRL now plans to offer related tests from pinpointing the genetic basis of sleep disorders as well as genetic examinations to predict a child’s bone strength and height.
jacob.k@livemint.com
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First Published: Sun, Aug 01 2010. 11 35 PM IST