SCIENTISTS LINK 2 GENES TO DIABETES

Scientists have identified two genes that cause a variant of the most common kind of diabetes, a surprising finding that might lead to new treatment.

Neither gene had been a suspect in the disease, and the new work "opens up a whole new pathway that has to be explored" for understanding diabetes, researcher Graeme Bell said.So far, it's not clear why defects in either gene sabotage the body's efforts to control blood sugar levels, he said.

The vast majority of diabetes is Type 2 disease, which affects about 15 million Americans. It usually develops in people older than 40, especially if they're overweight.

In contrast, the variant caused by the genes usually appears before age 25, often in adolescence or childhood. Together, the genes may account for 2 percent to 5 percent of Type 2 cases, Bell said.

Bell is a professor of biochemistry, molecular biology and medicine at the Howard Hughes Medi-cal Institute at the University of Chicago. He and an international team of researchers presented their findings in Thursday's issue of the journal Nature.

In diabetes, blood sugar levels rise out of control because the body doesn't secrete enough insulin, doesn't respond normally to insulin or has both problems.

Diabetes can lead to such problems as kidney disease, blindness and nerve damage. The nerve damage and impaired circulation in the feet and legs can lead to the need for amputation.

The variant caused by the genes is called maturity-onset diabetes of the young, or MODY. Another MODY gene had been found before, and Bell said at least one more remains to be uncovered.

The two genes in his study were already known to scientists, mostly for turning on other genes in the liver. The genes are also active in the intestine, kidney and the pancreas, which makes insulin, but it's not clear what they do in those organs.

People with MODY don't secrete enough insulin to handle high blood sugar levels, and it's not clear yet why defects in the two genes would lead to that problem, Bell said.