Scientists from Harvard Medical School (HMS) are working to cure leukemia, the cancer of the blood, with help from overseas.

Working with researchers from Germany's Munich University, they have most recently identified an altered gene--common in most people--that is necessary for normal cell growth, said Daniel G. Tenen, an associate professor of medicine and the U.S. organizer of the project.

While a few leukemia patients also have the gene in its altered form, most have a different form of the gene. Without the altered gene, leukemia could develop.

"The gene acts as a switch for the formation of blood cells," Munich University Professor Wolfgang Hiddemann told a German newspaper.

Leukemia is a type of cancer that causes overproduction of white blood cells, crowding out other blood elements. Symptoms include irregular fever, bleeding from the gums and anemia.

"[There are] changes in genes that cause them to lose their growth control," said Richard A. Van Etten, an associate professor of genetics at HMS who also worked on the project.

Genetic abnormalities, certain viruses and exposure to toxic chemicals are all causes of leukemia. No definite cause of leukemia is yet known.

Tenen said the research could lead to new treatments for leukemia. The scientists plan to use the information to develop new therapies for leukemia, using genetic engineering as well as radiation therapy.

"It's clearly going to tell us something about how leukemia develops," Tenen said.

Though HMS scientists perform most of the research in their labs, the Munich team has provided an abundance of blood samples. Tenen said he has received about 120 samples from Munich clinics.

HMS and Munich University have been collaborating on this research for about the last two years. Hiddemann, a hematologist, met with Tenen in Grainau, Germany for their first workshop last month.

"[The project] is designed to bring together clinicians in Munich and research at Harvard," Van Etten said. "[The collaboration] started informally with personnel transfer between Harvard and Munich."