Study Report

Reference	Kondo, K.,2013 PMID: 23967141
Citation	Kondo, K., Ikeda, M., Kajio, Y., Saito, T., Iwayama, Y., Aleksic, B., Yamada, K., Toyota, T., Hattori, E., Ujike, H., Inada, T., Kunugi, H., Kato, T., Yoshikawa, T., Ozaki, N., Iwata, N., 2013. Genetic Variants on 3q21 and in the Sp8 Transcription Factor Gene (SP8) as Susceptibility Loci for Psychotic Disorders: A Genetic Association Study. PloS one 8, e70964.
Disease Type	bipolar disorder & schizophrenia
Study Design	case-control
Study Type	Candidate-gene association study
Sample Size	BD = 1,012, SCZ = 1,032 and control = 993
SNP/Region/Marker Size	48 SNPs
Predominant Ethnicity	Mongloid
Population	Japanese
Gender	1,012 patients with BD[51.8% female], 1,032 SCZ (48.3% female) and 993 healthy controls (51.1% female).
Age Group	adults : 1,012 patients with BD[Mean age (SD) = 50.7(14.3) years], 1,032 SCZ (48.3% female,Mean age (SD) =46.8(14.8) years) and 993 healthy controls (51.1% female, Mean age (SD) = 49.7(14.0) years).

Sample Diagnosis	DSM-IV
Replication Size	BD = 821, SCZ = 1,808 and control = 2,149
Technique	genotyping
Statistical Method	All of the statistical procedures were calculated using PLINK version 1.07.
Result Summary	Eight SNPs revealed nominal association signals for all comparisons (Puncorrected<0.05). Among these SNPs, the top two SNPs (associated with psychosis: Pcorrected = 0.048 and 0.037 for rs2251219 and rs2709722, respectively) were further assessed in the second-set samples, and we replicated the signals from the initial screening analysis (associated with psychosis: Pcorrected = 0.0070 and 0.033 for rs2251219 and rs2709722, respectively). The meta-analysis between the current and previous GWAS results showed that rs2251219 in Polybromo1 (PBRM1) was significant on genome-wide association level (P = 5x10(-8)) only for BD (P = 9.4x10(-9)) and psychosis (P = 2.0x10(-10)). Although the association of rs2709722 in Sp8 transcription factor (SP8) was suggestive in the Asian population (P = 2.1x10(-7) for psychosis), this signal weakened when the samples size was increased by including data from a Caucasian population (P = 4.3x10(-3)). CONCLUSIONS: We found 3p21.1 (including PBRM1, strong linkage disequilibrium made it difficult to pinpoint the risk genes) and SP8 as risk loci for BD, SCZ and psychosis. Further replication studies will be required for conclusive results.