University of Texas Southwestern Medical Center researchers said the identification of the gene, IRAKi, and its location on the X chromosome might help explain why females are 10 times more susceptible to the disease than are males.
The findings might also have therapeutic implications, said Dr. Chandra Mohan, a professor of internal medicine and senior author of the study.
"Our work also shows that blocking IRAK1 action shuts down lupus in an animal model," said Mohan. "Though many genes may be involved in lupus, we only have very limited information on them."
Locating IRAK1 on the X chromosome also represents a breakthrough in explaining why lupus seems to be gender-linked, Mohan said, noting that for decades, researchers focused on hormonal differences between males and females as a cause of the difference.
The multicenter study involved 759 people who developed lupus as children, 5,337 patients who developed it as adults and 5,317 healthy controls. Each group comprised four ethnicities: European-Americans, African-Americans, Asian-Americans and Hispanic-Americans.
The study appears in the online edition of the Proceedings of the National Academy of Sciences.