"We are now approaching the ultimate goal in providing tailored medical treatment and therapies to suit Thai people," Wasun Chan-tratita, coordinator of the project to identify specific genetic patterns of Thais, said yesterday.

Wasun, head of virology and molecular biology at Ramathibodi Hospital, said Thailand was the fourth country in Asia - after Japan, China and Malaysia - to identify the single-nucleotide polymorphisms (SNPs) that can influence responses to certain drugs.

The project's second phase, which will focus on SNPs of people who have suffered a particular disease, would start early next year and run for six months to one year.

SNPs are units of DNA base-pairs that may vary from one person to the next. All humans share 99.9 per cent of their DNA base-pair sequences, with sequence variations of only 0.1 per cent, equivalent to one million DNA base-pairs. Wasun said his project focused on SNPs located on the genes that could predispose people to disease or influence responses to certain drugs.

Funded by the Thailand Centre of Excellence for Life Sciences (TCELS), the project was conducted by scientists from leading institutions here and abroad. The parties collaborating on the project are Mahidol University, Chulalongkorn University, the Mental Health Department, Japan's Riken Yoko-hama Institute and Yale University of the United States.

To complete the first phase, 280 healthy people from four regions - North, South, Central and East, with 70 people from each region - were selected as a group of sampling subjects. Blood samples of all 280 were taken so that DNA and sequences could be isolated by two Thai scientists stationed at the Riken Yokohama Institute.

The genetic patterns of the 280 subjects can represent some 65 million Thais, Wasun said.

"An acceptable number in the international community is only 100 samples. It's true that the more samples, the more precise the information, but 280 is acceptable."

For the second phase, 100 people would be recruited as a sampling group for one of three diseases that the project was considering - heart, cancer and psychiatric disease - or all three. One-third of all drugs available in the world is for the three diseases, he said.

The SNP research is part of the big phamacogenomic research project of TCELS. Dr Thongchai Thavichachart, CEO of TCELS, said the whole project would help medical treatment of Thais become more effective. Currently, research on the effectiveness of drugs is conducted on non-Thais.

"The SNP and phamacogenomic studies will help doctors prescribe drugs and provide treatment better fitted to Thais," he said.

Pennapa Hongthong

The Nation