Researchers in Hong Kong have uncovered a genetic quirk that could explain why some people fell sick with SARS during the outbreak of the pneumonia-like disease in 2003 while others remained healthy. Researchers led by Lin Chen-Lung of the University of Hong Kong carried out a DNA profile of 285 people infected with Severe Acute Respiratory Syndrome (SARS).The profiles were then compared with those of three groups of other people, totalling 842 individuals, who did not get infected.Persons who had repeat sections of code in a gene called CLEC4M were 30 percent less likely to catch the disease, they found.The protection only occurred, though, among people who had the repeats in both chromosomes for this gene.CLEC4M encodes a protein known as L-SIGN, which is a cellular receptor -- a binding site on the surface of the cell.The researchers believe that, among those with the CLEC4M protection, the intruding SARS virus sticks to the receptor and is eventually degraded.L-SIGN is found in the liver and lymph nodes. It has been implicated in previous research into infection by the hepatitis C virus as well as the AIDS virus.SARS killed about 800 people in an epidemic centered on Hong Kong and China before it was mastered by contain-and-control measures, including quarantines, health checks on travellers and distribution of face masks.The research is published online on Sunday by Nature Genetics, part of the London-based Nature group of journals.
