A TEAM AT UCLA and Cedars-Sinai Research Institute in Los Angeles has narrowed the search for a gene causing the mysterious autoimmune disease lupus to a small region of the vast human genome. The finding should lead to better understanding of the causes and, eventually, to new treatments for the disorder, which affects as many as 2 million Americans.

In the disease, known clinically as systemic lupus erythematosus, or SLE, the body attacks itself, damaging a broad variety of internal organs. Until the current findings, reported Wednesday in the Journal of Clinical Investigation, researchers had little idea what causes lupus, although it is clearly a combination of genetic susceptibility and environmental factors.

"The finding that this gene appears to play a role across ethnic groups is very exciting. It suggests that this is going to be an important gene for explaining what causes lupus," said Dr. Susana Serrate-Sztein of the National Institute of Arthritis and Musculoskeletal and Skin Diseases.