Reported p-values are taken for each of the Illumina550 probes on the genome, then logged and minused for visualization purposes. These p-values have not been Bonferroni adjusted. US cases had an affected sibling. 96% of German sample reported both parents and grandparents were born in Germany. The German sample was used to replicate the US sample. The following -conditions were applied to the US sample: pval < 0.05, Odds Ratio > 1.4 or < 0.71, -Relative Allele Frequency > 0.05, required to be near a known gene, -and finally replicated in the German sample with pval < 0.05. The results +conditions were applied to the US sample: pval < 0.05, Odds Ratio > 1.4 or < 0.71, +Relative Allele Frequency > 0.05, required to be near a known gene, +and finally replicated in the German sample with pval < 0.05. The results left 88 SNPs in 80 genes.
When individually genotyped, 76% remained significant in US, and 36% of those remained significant in the German sample. Combined p-values were also calculated for the SNPs yielding the most significant find rs1012053 pvalue = 1.5e-8 for the gene DGKH diacylglyceral kinase, which is still significant after Bonferroni adjustment. DGKH protein is key in the lithium-sensitive phosphatidyl inositol pathway. Several other risk SNPs were identified of small effect.
For the complete dataset, visit The National Instututes of Mental Health (NIMH) MAP Genetics Web Site.