The follow-up sample consisted of 1,024 German males recruited at the same sites and under the same protocol as the patients who were entered in the GWAS (Mannheim N=256; Bonn/Essen/Düsseldorf/Homburg N=149; Mainz N=63; Munich N=136; Regensburg N=420). Since most of the patients with an earlier age at onset had already been included in the GWAS, age at onset for the follow-up study was necessarily less stringent and defined as < 45 (median=30, mean±std=29.3±7) years. Phenotypes and genotypes resulting from GWAS are stored in a comprehensive database at the Institute for Medical Biometry, Informatics and Epidemiology in Bonn (IMBIE).
