Transmission disequilibrium test and haplotype analysis of the NOTCH4 gene in Japanese patients with schizophrenia

A recent study reported that the NOTCH4 gene was highly associated with schizophrenia in the British population. To confirm this association for another population, a case–control study was conducted and a transmission disequilibrium test (TDT) analysis was performed on a group of Japanese subjects (235 pairs of schizophrenia patients and controls, and 78 trios consisting of probands and their parents) using two single nucleotide polymorphisms and three microsatellite markers for the NOTCH4 gene. Haplotype analysis was also studied in case–control and family based data sets. In all markers except for (CTG)n (P = 0.012, before correction for multiple testing), no differences were found in the case–control study. The TDT analysis also revealed only a weak transmission disequilibrium in (TTAT)n (genotype‐wise P = 0.012). The finding of the present study could not support the original findings that the NOTCH4 gene itself is associated with susceptibility to schizophrenia.