International research led by Israelis has discovered the genetic basis for the serious and sometimes fatal autoimmune skin disease – pemphigus vulgaris – that is relatively common among Jews and some Arabs.The team of researchers, headed by Prof. Eli Sprecher of Tel Aviv Sourasky Medical Center, worked together with Prof. Ibrahim Saleh of the University of Luebeck in Germany. The research, just published in the Journal of Investigative Dermatology, showed that variations in the gene ST16 influence the genetic tendency of Jews and Egyptians to develop the disease. Pemphigus vulgaris is exhibited by blistering and sores on the skin and mucus membranes. The immune system produces antibodies against specific proteins in the skin and mucus membranes, and the antibodies break the bonds between skin cells. This leads to the formation of a blister. About half of sufferers first develop painful blisters and sores in the mouth, followed by blisters on the skin that may come and go. It is 40 times more common among Jews than in the general population of the world.The skin of those with pemphigus vulgaris separates easily when the surface of unaffected skin is rubbed sideways with a cotton swab or finger. This is called a positive Nikolsky’s sign. Severe cases of pemphigus may need wound management, similar to the treatment for severe burns. People with this condition may need to stay in a hospital and receive care in a burn unit or intensive care unit.Treatment is aimed at reducing symptoms, including pain, and at preventing complications, especially infections. In addition to medications, severely ill patients may undergo plasmapheresis, in which antibody-containing plasma is removed from the blood and replaced with intravenous fluids or donated plasma. Without treatment, this condition is usually life threatening. Severe infection is the most frequent cause of death. With treatment, the disorder tends to be chronic, and side effects of treatment may be severe or disabling.Dr. Ofer Sarig, who participated in the research, said that since the disease is rare in general populations but quite common among Jews, the hospital was able to provide the largest number of participants in the genetic study. The rarity in the general population is what delayed the discovery, added Sprecher, who is chief of dermatology at Sourasky.The study found that people containing the mutant gene are six times more likely to develop pemphingus vulgaris than those lacking the defect.Sarig noted that with the identification of the gene, Sourasky researchers are developing new ways to treat the disease in the future.