A newly identified gene mutation that causes severe combined immunodeficiency (SCID), also known as “bubble boy” disease, is described in a French study in the Nov. 15 issue of the Journal of Clinical Investigation.A number of genetic abnormalities that cause SCID have already been identified. These genetic defects impair the immune system. People with SCID suffer from numerous serious or life-threatening infections.In this study, researchers focused on three families who had infants with SCID of an unknown molecular type. The study found that a complete deficiency in the CD3 epsilon chain of the T-cell receptor, which binds foreign antigens and targets them for destruction, was the cause of SCID in these infants.Identification of this new mutation could prove important, Dr. Rebecca H. Buckley, a pediatrician at Duke University Medical Center, wrote in an accompanying commentary.
