Psoriasis is an autoimmune disease that causes red, itchy, scaly patches on the skin which can also affect the joints, a condition knows as psoriatic arthritis. It is estimated that 7 ½ million people in the U.S. are afflicted with the disease.
A research team led by scientists from the University of Michigan and the University of Utah School of Medicine have identified four new DNA “hotspots” that increase the risk of psoriasis.
The research team was led by dermatologist Dr. James T. Elder. Dr. Elder also leads a group at the University of Michigan that has an international reputation for its work in the field of psoriasis genetic research.
The study included a genetic scan of millions of genetic mutations by taking advantage of a new technology called genomewide association studies (GWAS). In this case, the analysis of 10 million mutations determined a total of 438,670 gene mutations that were determined to be potential causes for psoriasis.
Two groups of patients, 1,359 psoriasis patients and 1,400 controls without psoriasis, had their DNA compared to the 438,670 potential mutations. This lead to the identification of 18 potential DNA sites with the highest association with psoriasis.
The study was then expanded to include 5,048 people with and 5,051 people without psoriasis. This narrowed to potential “hotspots” to seven.
Those seven include three that were previously identified:
The four additional genes that were identified are:
As part of their report, the team said that genetic signals from TNFAIP3 and TNI1 may be at fault regulating the TNF-alpha induced inflammation of psoriasis and psoriatic arthritis. TNFAIP3 and TNI1 are also associated with two other autoimmune diseases, lupus and rheumatoid arthritis.
The team says that once all the gene mutations associated with psoriasis have been indentified, they may be able to develop a genetic profile to predict the risk of developing the disease, the type of disease, and response to treatment.
Their report was published in the January 25th online edition of Nature Genetics.