Chinese scientists say they have made a genetic breakthrough involving a young woman in Southwest China's Sichuan Province that will enhance lifesaving bone marrow transplant treatments in leukaemia patients.

The discovery of a new HLA-B allele was made at the HLA (human leukocyte antigen) Typing Laboratory at the Institute of Blood Transfusion at the Chinese Academy of Medical Sciences.

It was found by researchers who were completing blood sample typing for a potential female bone marrow donor in the provincial capital Chengdu.

The 25-year-old woman known as "Angel" was found to have something abnormal in the length of her HLA-B gene.

"It looked different compared to normal reaction patterns," said Dr Chen Qiang, a research fellow at the institute.

"It didn't seem like a gene mutation. I think it's rare,"

The results confirmed the existence of a new allele when there was no match of any combination of another like it.

"I suppose it might be an allele typical of Sichuan natives."

Chen said. "But we need to develop a special reagent which would help us in our search for the origin. It's still early to make any conclusions."

Chen is echoed in his caution by Wang Hongguang, director of the Biology Center of the Ministry of Science and Technology, who told China Daily that further tests must still be done to understand more characteristics of the discovery.

It is still too early to say how the finding will specifically aid bone marrow transplant patients, Wang noted. In China, leukemia patients increase by 40,000 each year.

Currently, there are more than 4 million patients waiting for bone marrow transplants.

A successful transplant depends on how well the donor's human leukocyte antigens (HLA) match those of the receptors.

The laboratory, with the help of counterpart labs in the United States, used DNA tests to check all of Angel's HLA-B gene.

The Chengdu-based lab has done tests of 3,000 bone marrow donors and Angel is the only person detected with the new allele.

Angel seems nonplussed by the whole affair.

"The reason I want to become a volunteer donor is simple," Angel said. "I just want to help those suffering from disease."

(China Daily January 7, 2004)