We evaluated the impact of age on the main identified risk locus on chromosome 8. We corrected for age using age coded as a binary variable with the mean age of cases (24,77 years (standard deviation =5.32)) as a guideline for the cut-off, grouping all individuals with age < 25 into one group (1,164 cases; 29,818 controls) and age >24 into another group (1,223 cases; 19,167controls). Due to the low age-span among cases it did not make sense biologically to divide the cases into smaller age-bins. Correcting for age did not have an impact on the strong association of the risk locus on chromosome 8 (rs5637282; P=1.082x10−11).
