A team from the University of Michigan looked for the gene -- called PSORS1 -- in more than 2,700 people from 678 families in which at least one family member had psoriasis.
According to the researchers, PSORS1 is the first genetic determinant of psoriasis to be definitively identified in a large clinical trial. The finding may help in the development of new, more effective treatments for the disfiguring inflammatory skin disease.
To develop psoriasis, people must inherit several disease-related genes and also be exposed to one or more environmental triggers, such as a strep infection, the researchers noted.
"For every individual with psoriasis who carries the PSORS1 gene, there are 10 other people with the gene who don't get psoriasis," study director Dr. James T. Elder, a professor of dermatology and of radiation oncology, said in a prepared statement.
The PSORS1 gene is actually one of more than 20 different varieties of a gene called HLA-C, one of several genes that regulate how the immune system fights off infection.
While Elder and his colleagues have identified the PSORS1 gene -- which they believe is the major gene involved in psoriasis susceptibility -- they said that much more research is needed to identify other genes involved in the development of psoriasis.
The findings appear in the May issue of the American Journal of Human Genetics.
HealthDay News, March 22, 2006