Acne vulgaris is a common inflammatory disease of the pilosebaceous glands characterized by inflamed (papules, pustules, nodules and cysts) and noninflamed lesions (comedomes) on the face, neck, chest and back. The prevalence of acne in adolescents has been reported as being between 35% and 90%, depending on the method of classification, with peak incidence occurring at between 14 and 17 years in females, and 16 and 19 years in males (Stathakis et al, 1997; Kilkenny et al. 1998). As well as the physical pain and discomfort that acne produces, it is well documented that acne sufferers experience higher levels of psychological distress, are more self-conscious and have a poorer self-image than age-matched controls. A possible role for genetic factors in the development of acne is based on the observation that relatives of affected individuals are at increased risk of developing acne compared with unrelated individuals. However, related individuals share similar environments as well as genes. By using the classical twin design which compares the similarity of monozygotic (MZ) twin pairs with that of dizygotic (DZ) twin pairs I was able to show previously that acne is a highly heritable trait (Evans et al. 2005).

No group has performed a genome-wide association study of acne to date. This study will combine the power of the ALSPAC, QIMR and TwinsUK cohorts to detect common variants underlying risk of acne/acne severity in a meta-analysis of genome-wide association studies. Variants which are shown to be associated with acne will be followed up using single SNP genotyping in the remainder of the ALSPAC cohort for whom genome-wide data is not available.