Scientists and clinicians from several research institutions in Singapore have established a new genetic databank containing the completed whole-genome sequencing (WGS) data of close to 5,000 Singaporeans. The study, published in Cell on 17 October 2019, is the world’s largest WGS analysis of Asian populations, particularly of Indian and Malay populations in the world, and provides insights on the genetic diversity of Asian populations that could enable more accurate diagnosis of genetic diseases, empower the research of chronic diseases and guide prevention and targeted therapies.
The institutions involved were: Agency for Science, Technology and Research (A*STAR)’s Genome Institute of Singapore (GIS), National University Health System (NUHS), Singapore Eye Research Institute (SERI), Tan Tock Seng Hospital (TTSH), National Neuroscience Institute (NNI), Khoo Teck Puat Hospital (KTPH), National University Hospital (NUH), SingHealth Duke-NUS Institute of Precision Medicine (PRISM), National University of Singapore (NUS) and Singapore General Hospital (SGH).
As a consequence of their population histories, populations from different parts of the world show significant genetic diversity. Asian populations have not been extensively studied and their genetic make-up is poorly understood, which has hindered efforts to discover disease-associated genes that impact on the health of individuals from these populations. Singapore consists of three major ethnic groups (Chinese, Malay, and Indian), which capture 80% of Asia’s diversity. Hence, Singapore investigators performed WGS on close to 5,000 Singaporeans (2,780 Chinese, 903 Malays, and 1,127 Indians) over two years.
The findings include a noticeable degree of genetic intermingling among the three ethnic groups, of which Chinese and Malays are more closely related. It suggests that Malays split from Chinese about 24,800 years ago and experienced significant gene inflow with East Asians about 1,700 years ago, coinciding with the Austronesian expansion, a hypothesized historical migration of peoples from Taiwan/East Asia to Southeast Asia and further to remote Pacific and Oceania islands. In addition, the team identified 98.3 million genetic variants across the Singapore genomes. More than half of these have not been previously reported in public databases. It also identified 20 candidate loci for natural selection where genome sequences were altered as a result of survival and adaptation to local environments during human evolution. 14 loci were found to be associated with human traits and diseases.
(Sources: Agency for Science, Technology and Research; The Straits Times)