British and Chinese scientists have discovered a genetic variant that explains why Chinese populations may be more vulnerable to the H1N1 swine flu virus. Researchers say that the discovery of this variant could help doctors find people who are at high risk of severe flu, and prioritize them for treatment.
The discovery of the genetic variant known as rs12252-C, which is more common in the Chinese population than anywhere else, may also explain why new strains of flu virus often first emerge in Asia.
Tao Dong of Oxford University in England, who led the study, said:
"Understanding why some people may be worse affected than others is crucial in improving our ability to manage flu epidemics and to prevent people dying from the virus."
The researchers found that having the rs12252-C variant could increase the chances of severe infection by six times.
Researchers focused on the rs12252-C variant for this study because it is 100 times more common in Han Chinese, the predominant ethnic group in China, than in Caucasian populations indigenous to West Asia and Europe. In Caucasian populations the variant is present in the genetic makeup of about 1 in 3,000 people.
The study showed that the rs12252-C variant was present in 69 percent of Chinese patients with severe pandemic H1N1 in 2009, compared with just 25 percent who only had a mild version of the infection.
In 2009 and 2010, H1N1 swine flu swept around the world. Last week a study was published that suggested that at least one in five people around the world were infected, and that around 200,000 were killed in the first year of the outbreak. The World Health Organization declared a pandemic in June 2009.
The research was published on Tuesday in the journal Nature Communications.