Genetics plays an important role in causing psoriatic arthritis. Based on available evidence, there are multiple genes that are important in causing psoriatic arthritis. Most of these genes are important in immune function regulation. If you have a first degree relative with psoriatic arthritis, your chance of psoriatic arthritis increases up to 50 times. Almost 40% of the patient with psoriatic arthritis have a family history of psoriasis, suggesting the strong genetic role in causing this disease. But, one important concept to remember is, just having genetic risk factor does not always mean you will get the disease. There are multiple other environmental triggers that are key in causing the disease.