Researchers know that psoriasis develops from a combination of genetic factors, environmental triggers, and immune system dysfunction, but the exact causes of psoriasis are complex and still not fully understood. A recently published study has uncovered additional genetic clues to the hereditary factors of the disease that shed light on how psoriasis is passed down from one generation to the next.
The largest psoriasis genetic meta-analysis to date
The meta-analysis reviewed previous genome-wide association studies and examined the genetic sequences of about 40,000 Caucasian individuals. (Genome- wide association studies examine genetic markers across thousands of complete sets of DNA to find genetic variations associated with a specific disease.) Previous studies had identified 47 genetic markers that increase the risk of psoriasis in European-origin populations. This latest study is the largest meta-analysis focused on psoriasis and was successful in identifying 16 new genetic markers linked to psoriasis, increasing the known genetic markers to 63.1,2
First genetic association study to include self-reported data
One of the sets of genetic data came from the company 23andMe, which provides consumer DNA analysis and genetic reports. Individuals who purchase their DNA analysis through 23andMe have the option to participate in genetic research, providing their genome and personally reported information on their health to researchers. Authors of this latest study stated that the inclusion of the data from 23andMe was significant in 14 of the new 16 genetic markers.1
Genetic markers identified related to T-cell activation
Several of the new genetic markers identified involvement in the immune system function in psoriasis, including genetic markers that activate or impact the function of T-cells. T-cells are a type of white blood cell that are involved in the immune system response. In a healthy immune response, T-cells attack foreign invaders and release chemicals called cytokines that influence the entire immune response (including inflammation). In people with psoriasis, the immune response, particularly the inflammatory response, is over-activated, causing the symptoms of psoriasis.1,3,4