A*STAR's Genome Institute of Singapore (GIS) led an international team of researchers from Singapore, China, USA and Europe to conduct the world's first large-scale, trans-ethnic, genome-wide analysis of DNA samples taken from Caucasian and Chinese populations for the study on the chronic skin disease, psoriasis. Findings from the study were published in the scientific journal Nature Communications.
The researchers discovered four new genes that render people highly susceptible to psoriasis. By cross-referencing the sequence of 44 genes that influences psoriasis, which included the four recently discovered genes, between 8682 Caucasians and 5134 ethnic Chinese, the international team led by Prof Jianjun Liu, Deputy Director for Research Programmes and Senior Group Leader of Human Genetics found that 10 out of the 44 genes linked to psoriasis susceptibility were found only in Caucasians and not in ethnic Chinese. This finding helps to explain why psoriasis is ten times more prevalent in Caucasians than in ethnic Chinese populations.
The causes of psoriasis are not yet fully understood, but a number of risk factors are recognised as root causes, which include genetic and environmental factors, such as smoking, stress, obesity and alcohol consumption. The study takes some of the guesswork out of identifying the root cause responsible for the prevalence of psoriasis in Caucasian compared to ethnic Chinese populations.
"The discovery indicates that the ethnic difference of psoriasis prevalence is largely due to genetic causes," said Prof Liu. "With this knowledge, there is now a possibility to design therapeutic cures in an ethnic-specific fashion for psoriasis as there is currently no cure. The genetic differences in psoriasis susceptibility between ethnically varied populations call for more genetic studies within the Asian population."
"There are different types of treatments for psoriasis, with each addressing a different root cause of the disease. The only way for a patient to know which treatment best works for his or her condition is to try each over time - this will lead to added costs and time. The benefit of such genetic studies in psoriasis for example, allows the development of future genetic tests that will go a long way to help doctors take the guesswork out of figuring the root cause of disease and shortlist treatments that are known to be the most effective for that patient's condition," said Prof Huck-Hui Ng, Executive Director, GIS.