An Oklahoma Medical Research Foundation scientist's work may explain why lupus occurs more in women. Dr. Amr Sawalha discovered a gene on the X chromosome that likely plays a role in the autoimmune disorder. Women carry two X chromosomes but men carry only one.
Women develop lupus nine times more than men. Chromosomes are long pieces of DNA found in cells. Humans have 23 pairs. "This is the first gene to be related to adult (onset) lupus on the X chromosome,” Sawalha said, adding that he hopes the finding helps researchers understand why lupus is more common in women. The gene Sawalha studied, , plays a role in controlling many other genes, and a mutation in it likely predisposes a person to lupus. If the gene is unable to do its job, as in lupus patients, immune system T cells become overactive, resulting in the immune system turning on the body. "Basically, it makes the T cells abnormally active — hyperactive,” Sawalha said. Sawalha's findings appeared last month in the journal Plos One. The gene's discovery could lead to new therapies for lupus. Some 2 million Americans and 15 million people worldwide have the disease. Sawalha also is an assistant professor of medicine at the University of Oklahoma Health Sciences Center and a staff physician with the Veteran's Administration Hospital in Oklahoma City. Lupus can affect multiple organs, joints and skin. It can be life-threatening and has no cure. Patients are treated with drugs that suppress their immune systems. Researchers long have suspected the X chromosome played an important role in lupus, according to the report.