Genome-Wide Association Study Reveals a Novel Locus for Male Pattern Baldness. J. B. Richards1,2, X. Yuan3, F. Geller4, D. Waterworth3, V. Bataille2, D. Glass2, K. Song3, G. Waeber5, P. Vollenweider5, B. Walters4, U. Thorsteinsdottir4, A. Kong4, H. Stefansson4, K. Stefansson4, T. D. Spector2, V. Mooser3 1) McGill University, Montreal, QC, Canada; 2) King's College London, London, United Kingdom; 3) Genetics Division, GlaxoSmithKline, King of Prussia, Pennsylvania, USA; 4) deCODE Genetics, Reykjavik, Iceland; 5) CHUV University Hospital, Lausanne Switzerland.
Objective: Androgenic alopecia is a highly heritable polygenic disorder of considerable social significance, whose genetic architecture remains to be described. We conducted a genome-wide association study for androgenic alopecia Methods: A genome-wide association study was performed assessing 370,102 single nucleotide polymorphisms (SNPs) from the Affymetrix gene chip human mapping 500k array using standard protocols in 578 male cases (defined as Hamilton grade alopecia V-VII prior to age 65) and 547 male controls (defined as Hamilton grade I-II before age 75). The lead SNPs from novel loci achieving a p-value of ¡Ü10-5 were tested for replication in two independent cohorts involving 1,100 men from the United Kingdom and Iceland, phenotyped for androgenic alopecia and hair loss, respectively. Additionally, this SNP was tested for association with hair loss in 878 women from Iceland. Results: The previously replicated locus near AR on the X chromosome achieved genome-wide significance (p = 5.0 x 10-11). 26 SNPs achieved a p-value of ¡Ü10-5 from a novel locus on chromosome 20 in the discovery genome-wide association scan. The lead SNP from this locus was strongly associated with androgenic alopecia (p = 3.2 x 10-10) in the discovery cohort and was also associated with androgenic alopecia in 366 men from the British TwinsUK cohort (p = 1.5 x 10-3) and hair loss in 734 men from the Icelandic cohort (p = 6.1 x 10-3). The combined odds ratio for androgenic alopecia in men for all cohorts was 1.6 (p = 6.7 x 10-13). Additionally, this SNP was associated with hair loss in women from Iceland (p = 0.01). Interpretation: Our findings demonstrate that a novel locus on chromosome 20 is strongly associated with androgenic alopecia.
