The GWAS of STAR*D for the MDD phenotype (1,221 cases and 1,636 controls) did not produce genome-wide significant findings. Several regions with modest levels of significance in STAR*D were more strongly supported in the meta-analysis, including SLC18A1, ATP6V1B2 and PLEKHA7 for the Broad phenotype and SYN3 for the Narrow phenotype. Because genotypes were assayed on three different platforms, stringent QC measures were required to avoid spurious findings. The very low genomic control inflation factor (λ) suggests that these measures succeeded, but they also reduced the number of SNPs (260,474) available for analysis.
