Acne vulgaris (acne) is a common inflammatory disorder of the cutaneous pilo-sebaceous unit. Family and twin studies indicate a substantial genetic contribution to acne susceptibility with heritability estimates of 78 and 81%. Genome-wide association studies (GWAS) have made a substantial contribution to the understanding of the genetic basis of several common cutaneous inflammatory disorders. Here we perform a genomewide association analysis, comparing severe cases of acne with controls in females and males separately to identify and replicate genetic determinants.