Two research groups working separately have discovered a gene on the X chromosome that, when mutated, can lead to a dangerous autoimmune disorder and sometimes diabetes.
One of the groups, led by scientists at the University of Washington in Seattle, reports in the January Nature Genetics that the gene, called FOXP3, can be mutated in many ways. By checking blood samples from members of families afflicted with the autoimmune disorder—known as IPEX, which stands for immune disregulation, polyendocrinopathy, enteropathy, X-linked syndrome—the researchers uncovered the problematic mutations.
Although the protein encoded by the normal form of FOXP3 influences the immune system, its mechanism remains unknown, says coauthor Hans D. Ochs, an immunologist at the University of Washington School of Medicine. The scientists learned from animal studies that some defective versions of the protein cause out-of-control proliferation of T cells an