Saturday, August 23, 2008

Viết tiếp về di truyền trong thể thao

Hôm nay thấy trên tờ Sydney Morning Herald có bài về gien và thể thao! Họ còn trích dẫn nghiên cứu của bà K. North, một đồng nghiệp của tôi và từng cộng tác trong nghiên cứu gien ACTN3. Bài báo cho biết trong số tất cả các vận động viên tranh tài trong cuộc thi chạy 100 m đều có nguồn gốc từ Tây Phi. Thì y chang như tôi đã tiên đoán mà! :-) Chúng ta không hi vọng gì đoạt giải điền kinh này.

Cuốn sách của Jon Entine mà bài báo đề cập đến (Taboo - Why Black Athletes Dominate Sports And Why We're Afraid To Talk About It) thật ra là một cuốn gây ra nhiều tranh cãi. Ông này có vẻ kì thị, nhưng những dữ liệu ông ấy trình bày trong sách thì không có gì sai. Chỉ có cách diễn giải thôi: cùng một dữ liệu, nhưng diễn giải thì có khi không khách quan.

Thế thì vấn đề là gì? Việt Nam có nên xét nghiệm gien để chọn vận động viên để đào tạo cho các kì tranh tài Thế vận hội? Tôi nghĩ là nên. Nhưng xét nghiệm gien nào thì còn là câu hỏi lớn. Câu hỏi này cũng chính là cơ hội cho các nhà di truyền học nước ta.


Out of Africa: the speed gene genie

Andrew Stevenson August 23, 2008

GOLD medallists raise their fists in jubilation and sleep well at night knowing they're the best in the world. Drawn from about 200 countries, they compete against one another under the utopian banner, "One world, one dream".

But did they really beat the world or do the specific genetic characteristics of different population groups mean that the Olympics - open to ever-wider participation in the shrinking global village - are actually a race narrowed down to rivals from their own distinct ethnic group?

In Beijing, for the first time at an Olympic Games, every competitor in the men's and women's 100 metre sprint finals traced their ancestry to West Africa. Even more remarkably, 15 of the 16 runners are descendants of the slave trade, living in the Caribbean or the US. Jeanette Kwakye is the exception, born in England of Ghanaian parents.

The fastest runner in Australia this year, Adam Miller, of Penrith, on his best time would have trailed Usain Bolt - who backed up to win the 200 metres with a remarkable pair of world record times - by nearly a dozen metres.

White men cannot run. But they can jump and lift huge weights and swim, if not like fish, then faster than anyone else on the planet. Welcome to the race race, where winners are not just grinners, they're athletes who were smiled on by the genetic gods, argues Jon Entine, author of Taboo - Why Black Athletes Dominate Sports And Why We're Afraid To Talk About It." To a large degree it's not who works the hardest [who wins] but who had the genetic gods look down on them with favour and the Bolts of the world fit that category," he said.

The malignant hand of the slave trade might have already played a role, intervening in natural selection with the strongest and fittest West Africans loaded on slave boats bound for the Americas, contributing to a dominance of Caribbean sprinters several centuries later. A Jamaican urologist, William Aiken, has proposed another, speculative, suggestion about why a nation of 2.8 million has achieved so much.

"Since Jamaica was one of the last stops to be made by the slave ships, it ensured that only the most resilient and fittest of slaves were alive to disembark," he wrote in an article connecting sprinting prowess with high rates of prostate cancer, both of which he suggested could be linked to testosterone levels.

The truth is geneticists have identified only a handful of genes that affect human physical performance. Kathryn North, of the Institute for Neuromuscular Research at the Children's Hospital at Westmead and the University of Sydney, has shown there is a common genetic variant in the fast-twitch muscle gene alpha-actinin-3 that renders it inactive in about 20 per cent of European populations and at least 1 billion people worldwide.

But the active form of this single "sprint gene" is found in all Olympic sprinters of European background and almost all Africans. That is one gene and many more wait to be revealed.
But the little already known indicates the power of genes - if you don't have alpha-actinin-3, you are unlikely to win the 100 metres. But the inactive form could set up a career in distance running. North's team created mice with the inactive form which could run 33 per cent further than mice with the sprint gene before becoming exhausted.

North is anxious not to rule out cultural influences such as diet and coaching, and psychological traits such as the so-called "mongrel" gene that fuels the will to win. But she agrees some distinct populations have a huge competitive advantage in certain events.

"I don't think we can ignore that we all look and perform differently in different situations," she said. "It's not that one ethnic group has an overall advantage; it's just there are strengths and weaknesses in different populations throughout the Earth that are influenced by the environment in which they have lived and in which certain traits have evolved."

Entine said there were athletic hot spots around the world based on distinct body types. East Africans dominate distance running to almost the same extent as those originally from West Africa are dominating sprinting.

"The word 'race' doesn't really apply. Look at East Africa versus West Africa. They're all Africans but the body types of Kenyans and Ethiopians are very different to West Africans'," he said. "And you can see it in swimming. You can make all kinds of cases that blacks are culturally disadvantaged in swimming but the reality is the black body type is not suited to being great swimmers."

Intriguingly, debate about genetic influences on athletic performance has been hampered by cultural and political taboos, despite frank and open discussion of how illness and disease may be influenced by genetic variations. Perhaps the memory of the attempted racial hijacking of the Olympics in 1936 still lingers.

But identifying which variations in which particular genes contribute to success in any particular athletic endeavour is extremely challenging, with the answer still several years away.
"At the moment we know only of a couple of genes, probably less than 10, that have been shown to have some influence on the different types of human physical performance," North said. "There are probably hundreds of genes involved."

But, even when they are found, will they tell us anything the naked eye and a record book do not already confirm?

If you want a weightlifter, look for someone with shorter limbs in ratio to their torso and greater upper body strength, physical features more common to Caucasians. Similarly, 11 of the past 12 Olympic hammer-throw champions came from a handful of northern European nations.
"You don't need to do a molecular test to see if someone's tall and a stopwatch does a pretty good job of telling you if someone's fast," said Jason Gulbin, who runs the Australian Institute of Sport's talent identification program.

But a genetic profile might help determine whether athletes are in the right event, whether they have a significant capacity to improve, what sort of training load they can bear and their susceptibility to injury.

"The key point is to implement research to understand the value of genetic information and this is the area that spooks people. And they get caught up in, a) the race angle and, b) the genetic manipulation/gene therapy side of things. When people hear the g-word they jump to conclusions," Gulbin said.

Despite the potential benefit of using genetics as an extra tool to screen, manage and prepare athletes, the AIS has been barred from genetic research by a directive from the former federal sports minister, Rod Kemp.

The AIS director, Peter Fricker, believes now is the time to act or Australia risks being left behind.

"A year or two ago, because there are so many other things that make a champion, I thought we could wait and see what the scientists come up with. But I worry that, because you can see countries around the world starting to do the research, we need to be on the front foot," he said. "Australia has to be in the game and we have to do it really well and we have to get reliable information so we can make sense of our talent-screening strategies."

Fricker believes we are still a decade away from reliable genetic predictors of performance that are worth building into talent-screening programs.

"Where we might end up with all this research is with a set of genetic variations - and if you've got this one, this one, this one, this one and this one, the chances are you'll be a much better athlete than someone who's only got two of those genes," he said.

"Just in raw potential, that's what the scientists are interested in - to see how accurate and how reliable having that genetic information might be. If you had no other information at all, would it really help you select the next champion?"

But while scientists such as Fricker are more cautious - citing a list of environmental factors that influence performance - Entine has little doubt genes will be able to pick winners, arguing that many key behavioural traits, such as the ability to withstand pain and a willingness to take risk, could well have genetic bases.

"There's no question that in not too many distant decades you'll be able to know right off what the parameters and possibilities are to becoming a great athlete for someone when they're popping out of the womb," he said.


nguoi nha que said...

Anh đã có bài viết về Tây Nguyên.
Riêng lãnh vực thể thao VN, cũng mong anh nhảy vô tiếp. Trước 75, vận động viên vô địch chạy nước rút Miền Nam cũng có không ít gốc gác người Thượng ( Ba na...), chắc chắn yếu tố di truyền có vai trò trong đó. Ông Chánh Trinh ( Lý quí Chung ) cũng đã có bài viết đề nghị Nhà nước nên chú tâm tuyển lựa lực lượng này vô đội tuyển điền kinh quốc gia. Học viện bóng đá ( Arsenal ) ở Pleiku hình như tuyển được vài em.
Jamaica kỳ này họ chạy nhanh quá xá. Dù là nước ở Trung Mỹ nhưng chắc nguồn gốc là châu Phi qua hình dáng bên ngoài. Phải xem lại lịch sử lập quốc của họ để đoan chắc rằng Châu Phi không để mất phần lớn huy chương vàng vô tay Châu khác. Các anh chị Mỹ, Anh lên đường đua đa số là người gốc Phi hết.

Ngoc Quyen said...

Con xin phép được gọi bằng Thầy.
Con là sinh viên năm thứ 4 Khoa Dược của trường ĐH Y Dược. Đọc các bài viết của Thầy con được biết Thầy là một bậc trưởng bối giàu kinh nghiệm. Nay con phải chọn chuyên ngành để học trong các ngành học như Dược lâm sàng, Dược bào chế, Dược kiểm nghiệm....mà con thì phân vân quá không biết chọn ngành nào, con cũng không biết nhiều về các bộ môn này.Mong Thầy cho con xin một lời khuyên. Con rất mong nhận được lời chỉ bảo của Thầy.Con cám ơn Thầy.

Nguyễn Văn Tuấn said...

Có một nhóm trẻ ở Hà Nội sau khi đọc bài về điạ đàng ở phương Đông của tôi đã tiến hành một nghiên cứu di truyền ở người dân tộc thiểu số phía Bắc. Tôi có đề nghị làm cả ở Tây nguyên. Theo tôi biết thì công việc thu thập dữ liệu và mẫu máu đang tiến hành, và hi vọng nay mai chúng ta sẽ có dữ liệu tốt về câu chuyện "cội nguồn" này.

Tôi thấy cái challenge là làm sao tìm gien để chọn vân động viên. Cái khó ở đây là tìm một cái phenotype để đo. Vả lại, nói thẳng ra thì câu chuyện còn tế nhị ở chỗ nó mang màu sắc kì thị (mà có lẽ ở nước ta nhiều người ta chưa nghĩ đến).

Ngoc Quyen gọi tôi là "trưởng bối" sao mà nghe cứ như là truyện chưởng vậy? Không, không có bối với biếc ở đây. Nếu Quyen thích làm nghiên cứu thì tôi nghĩ đến theo ngành duợc lâm sàng vì ở đó có nhiều cơ hội hơn. Còn dược bào chế thì tôi e rằng ở nước mình chưa có điều kiện dồi dào để làm.

Viet Tuan said...

Kỹ năng làm khoa học của gs tuyệt với quá!