JAN/FEB 2016|| 9No child or young athlete should be subjected to genetic testing for
sporting talent or to boost performance, according to a consensus
statement published in the British Journal of Sports Medicine
(tinyurl.com/pbynzkn).
The scientific evidence for the effectiveness of these commercial
tests is simply far too weak to back their use, said the international
panel of 22 experts in the fields of genomics, exercise, sports
performance, disease, injury and anti-doping.
However, this lack of evidence has not hindered the growth of
DIY genetic tests, which claim to be able to spot children’s athletic
talent or tailor training to maximise performance. This burgeoning
market has prompted fears that the current limited level of
knowledge on the genetics of sports performance is being
misrepresented for commercial gain, the statement says.
The panel found 39 companies marketing tests associated with
sport or exercise performance or injury. In 2013 a similar review
found 22, but 14 of these have ceased trading, meaning that 25 new
companies have entered the market within the past 2 years.
Claims included: “Personalise your training based on your sports
genetics,” “Gives parents and coaches early information on their
child’s genetic predisposition for success in team or individual
speed/power or endurance sports,” and “We use your DNA results to
help you lose fat, get lean, build muscle, get fitter”.
For 21 of the companies the panel could not find out which gene
sequences and variants would be tested because this information
wasn’t provided. For the remainder, the average number of variants
tested was six, but ranged from one to 27.
The most popular genetic variants tested were ACTN3 R577Xand
ACE I/D, both of which have been relatively well studied. While there
is some evidence to suggest a link with enhanced physical
performance, it is very weak, rendering the predictive value of these
tests “virtually zero” according to the statement.
Of further concern is that several companies use the results to
market additional products, such as training advice and nutritional
supplements, for which the evidence is again limited.
The statement emphasises that the speed of change in gene
sequencing technology has far outpaced regulation or universally
accepted guidelines. Indeed, legislation varies widely among
countries and is non-existent in some.
The panel points out the importance of counselling before any
genetic test is taken, particularly as this may have implications for
health or life insurance. Furthermore, the sensitive nature of an
individual’s genetic information should be subject to the highest
level of security and confidentiality, but it is not at all clear what
happens to these data when one of these companies ceases trading.
“While further evidence will undoubtedly emerge around the
genetics of sport performance in the future, the data are currently
very limited,” the consensus statement says. “Consequently, in the
current state of knowledge, no child or young athlete should be
exposed to genetic testing to define or alter training or for talent
identification aimed at selecting gifted children or adolescents,” it
concludes.Mother Whale’s Cultural
Traditions Shape the
Genetics of Offspring
The migratory behaviour of endangered southern right whales,
learned from a whale’s mother in its first year of life, has helped to
shape the genetics and population recovery of the species.
Prof Robert Harcourt of Macquarie University says the findings,
published inScientific Reports(tinyurl.com/q593osq), offer an
insight into how cultural preferences can shape the genetics of a
mammalian species.
“Young whales acquire their migration preferences from their
parents in a practice known as migratory culture, causing them to
follow the same routes to get to their desired destination when
they grow older,” Harcourt said. “What is interesting about the
findings of this study is that they show that the migratory culture
actually has an effect on the genetic patterns that we observe in
both the summer feeding and winter calving grounds of Australian
southern right whales.”
The international group of researchers involved in the study
took up to 20 years to collect enough skin samples from southern
right whales in certain regions around Australia and New Zealand,
due to their endangered status. They then analysed the unique
DNA markers of each whale, which allowed them to build a map
of the population structure and relatedness in the species. Micro-
chemical markers revealed the feeding ground preferences of each
whale.
“Whales that showed similar feeding ground preferences were
more likely to be related, using both maternally inherited and bi-
parentally inherited DNA markers,” explained lead author Dr
Emma Carroll of the University of St Andrews in the UK. “There
were also significant differences in maternally inherited DNA
markers among winter calving grounds, consistent with the idea
that there is maternally directed learning of these migratory habi-
tats,” she added.
The researchers hope that their study will shed more light on
the current issues facing this large, long-lived species of marine
mammal, which is still recovering from the effects of whaling even
though the practice was terminated in Australia in 1979. “Knowing
the current genetic network of this species and their migratory
habits means we will be able to monitor them more precisely in the
future,” Harcourt explained.Southern right whale learn migratory patterns from their mothers,
which affects the population’s genetic structure.Evidence Is Weak for Genetic Testing of Sporting Talent
Credit: Rob Harcourt