EGR3 as a potential susceptibility gene for schizophrenia in Korea.

Early growth response (EGR) genes play critical roles in signal transduction in the brain, which is involved in neuronal activation, brain development, and synaptic plasticity. EGR genes, including EGR2, EGR3, and EGR4, showed significant association with schizophrenia in Japanese schizophrenic pedigrees. In particular, EGR3, which resides at the chromosomal location 8p21.3, was suggested to be a potential susceptibility gene in schizophrenia based on a study of Japanese cases. However, this requires further replication with an independent sample set. We investigated the association of the EGR3 and EGR2 genes, which were suggested as potential susceptibility genes for schizophrenia supported by both genetic association and postmortem brain expression studies, with schizophrenia in Korean patients. Along with 350 healthy individuals, 244 schizophrenic patients were analyzed. Among the four examined single-nucleotide polymorphisms (SNPs) of EGR3 (rs1008949, rs7009708, rs35201266, and rs3750192), SNP rs35201266 in intron 1 of the EGR3 gene showed a significant association with schizophrenia (P = 0.0008, χ(2) = 11.156, OR = 1.493), which withstands multiple testing correction. In addition, the "T-G-C-G" haplotype of EGR3 was under-represented in the patients with schizophrenia (P = 0.0073, χ(2) = 7.188, OR = 0.697). However, an association between the SNPs of EGR2 (rs2295814 and rs2297488) and schizophrenia was not found. These findings are consistent with the previous genetic association of the EGR3 gene in Japanese cohorts, which is the first replication concerning the association of EGR3 with schizophrenia in an independent cohort. Taken together, EGR3 could be suggested as a compelling susceptibility gene in schizophrenia.