Positive association between PDLIM5 and schizophrenia in the Chinese Han population

The PDZ and LIM domain 5 protein (PDLIM5) contains one PDZ (post-synaptic density-95/discs large/zone occludens-1) domain and three LIM (Lin-11, Isl-1, and Mec-3) domains, and is also known as Enigma homologue LIM domain (ENH) protein or LIM protein. DNA microarray analysis of post-mortem brains of schizophrenics has indicated up-regulation of the mRNA level of PDLIM5, and Horiuchi and colleagues reported two single nucleotide polymorphisms (SNPs) (rs2433320 and rs2433322) in the 5' region of the PDZ and LIM domain 5 gene (PDLIM5) to be significantly associated with schizophrenia in the Japanese population. On the other hand, no association with schizophrenia was observed by Kato and colleagues in a different sample of the Japanese population. In this study, we genotyped six SNPs (including rs2433320 and rs2433322) covering PDLIM5 in 507 schizophrenia patients and 530 normal controls recruited from Jiangxi Province, China. Although rs2433320 was negative in our samples, rs2433322 showed significantly different frequencies between cases and controls (P=0.000010). In addition, high linkage disequilibrium was observed between rs2433320 and rs2433322 (D'=0.880), and haplotypes constructed from the two SNPs were significantly associated with schizophrenia (global P=0.00019, even after strict Bonferroni correction). Our results provide further evidence to support PDLIM5 as a potential susceptible gene for schizophrenia.