Identification of PTPN22, ST6GAL1 and JAZF1 as psoriasis risk genes demonstrates shared pathogenesis between psoriasis and diabetes

The biological connections between psoriasis and diabetes have been suggested by epidemiological, immunological and genetic studies. To identify additional shared susceptibility loci and investigate shared pathogenesis between these two diseases, we genotyped 89 reported diabetes susceptibility loci in 4456 psoriasis cases and 6027 controls of Chinese population using the MassARRAY system from Sequenom. We discovered three significant associations at rs6679677 on 1p13.2 (P=6.15x10(-5), OR=5.07), rs16861329 on 3q27.3 (P=2.02x10(-4), OR=0.87) and rs849135 on 7p15.1 (P=6.59x10(-9), OR=1.78), which suggested PTPN22, ST6GAL1 and JAZF1 as novel susceptibility genes for psoriasis in Chinese population. Our findings implicated the involvement of T-cell receptor signalling pathway in the pathogenesis of psoriasis and further confirmed the shared genetic susceptibility between psoriasis and diabetes.