More heritability probably captured by psoriasis genome-wide association study in Han Chinese

Missing heritability is a common problem in genome-wide association studies in complex diseases/traits. To quantify the unbiased heritability estimate, we applied the phenotype correlation-genotype correlation regression in psoriasis genome-wide association data in Han Chinese which comprises 1139 cases and 1132 controls. We estimated that 45.7% heritability of psoriasis in Han Chinese were captured by common variants (s.e.=12.5%), which reinforced that the majority of psoriasis heritability can be covered by common variants in genome-wide association data (68.2%). The results provided evidence that the heritability covered by psoriasis genome-wide genotyping data was probably underestimated in previous restricted maximum likelihood method. Our study highlights the broad role of common variants in the etiology of psoriasis and sheds light on the possibility to identify more common variants of small effect by increasing the sample size in psoriasis genome-wide association studies.