Genome-wide association study identifies two novel susceptibility loci for trichilemmal cysts

Trichilemmal cysts (TC), also known as pilar cysts, are keratin-filled, subepidermal nodules originating from the outer hair root sheath. Recently phospholipase C delta 1 has been suggested to play a critical role in the formation of TCs. However, it is unknown if other genes contribute to TC formation. We conducted a genome-wide association study (GWAS) of 5,331 TC cases and 403,251 controls in a genetically British group. Our genome-wide scan revealed PLCD1, CLPTM1L, and TMED10|FOS as susceptibility loci for TCs. Additionally, we performed a follow-up GWAS on 2,806 epidermal inclusion cysts and 405,776 controls in the same population, without identifying any susceptibility loci.