Controls (N=626) were recruited from donors at the Northern Ireland Blood Transfusion Service (N=554) and from the Irish national police (N=38) and army reserve (N=34). Controls were briefly screened and were eligible if they reported no history of schizophrenia and all four grandparents born in Ireland or the UK. All participants gave appropriate informed consent. Recorded sex was verified by X/Y genotypes; cases were 68% male and 32% female, controls were 55% male, 45% female. This sample has ≥78% power to detect effects with minor allele frequency (MAF) ≥20% and allelic odds ratio (OR) ≥1.3.
