Studying the genetics of an indigenous Malaysian tribe may be the key to unlocking the mystery that has long perplexed scientists: why East Asians have light skin but lower skin cancer rates than Europeans.
An international group of scientists claim that understanding the differences in skin color genes between Asians and Europeans could lead to a better way to protect people from skin cancer.
Previously, researchers from the Penn State College of Medicine were able to identify a unique gene in Europeans that contributes to lighter skin color.
They found that Europeans possess mutations in the genes SLC24A5 and SLC45A2 that are largely responsible for their pigmentation, showing only single amino acid differences between Europeans and West Africans.
Researchers said that while East Asians are also light skinned, these European alleles were not present in people from countries like China, Japan and Korea, suggesting that, while both groups of people evolved lighter skin color for better production of vitamin D in northern climates where there is less sunlight, they did so in a different way.
Researchers believe that the difference in evolution also affects skin cancer rates.
While Europeans are 10 to 20 times more likely to develop melanoma than Africans, East Asians have the same melanoma rates as their African counterparts despite possessing a lighter skin tone.
Experts explained that this difference can only be explained when the gene mutations for East Asians and Europeans are found.
"By finding the differences, we have the potential to find ways to make people with the European ancestry genes less susceptible to skin cancer," Dr. Keith Cheng, professor of pathology at Penn State College said in a statement.
Identifying the mutations will be a challenge because it involves finding and studying a population that includes a blend of original African ancestry and East Asian ancestry, with little European contribution.
Researchers believe that one of the three indigenous populations from Peninsular Malaysia called the Senoi meet this condition. The Senoi people are believed to be descendants of a dark-skinned tribe called the Negrito, and a regional Mongoloid population of Indo-China, like the Proto-Malay.
Researchers explain that that because people from the Senoi tribe are darker than Northeast Asians, they will be able to focus on finding the primary genetic mutation of light skin color in Asians without seeing more advanced skin lightening mutations.
Researchers have recently collected blood samples from people in the Senoi tribe, and they hope that the samples will help them identify which mutation might be responsible for the skin color of East Asians, according to a study published in the journal PLoS ONE.
"As the world is becoming globalized, populations are becoming increasingly mixed," Researcher Khai C. Ang, a postdoctoral fellow in the Cheng lab, said in a statement. "Time is running out and it will become increasingly difficult to establish how East Asian skin colors evolved."
"Skin color has been tied to human welfare in modern history," Cheng concluded. "It is important for us as a species to realize that our skin color is determined by only a small number of minute changes in our DNA -- changes that have nothing to do with the value of human beings."