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Recently, Pimm et al. identified Epsin 4 on chromosome 5q33 as a susceptibility gene for schizophrenia in the British population, based on linkage and association evidence. In Pimm's case-control study, both the single polymorphisms and the individual haplotypes at the 5′ end of the gene showed genetic association with schizophrenia. Here, we report the first study evaluating the relevance of Epsin 4 and schizophrenia outside the British population. Markers showing positive results in the original work as well as two additional polymorphisms were genotyped in 308 Han Chinese family trios. Transmission disequilibrium analysis was used to test for association of single-locus markers and multi-locus haplotypes with schizophrenia. Although no individual marker was significant at the P=0.05 level, the haplotypes detected in our samples, different from those previously reported, showed strong evidence of association (most significant global P=0.0021). Our results indicate the presence of a locus near the 5′ end of Epsin 4 conferring susceptibility to the disease and provide further support for Epsin 4 as an important potential contributor to genetic risk in schizophrenia.Molecular Psychiatry (2006) 11, 395–399. doi:10.1038/sj.mp.4001780; published online 10 January 2006 [ABSTRACT FROM AUTHOR]

The article discusses a study on the copy number variation (CNV) of schizophrenic patients in the Chinese Han population. The study involved the recruitment of 155 residents from Shanghai who were diagnosed with schizophrenia, and performing genome-wide scans on subjects with structural variants greater than 100kb. It was found that among the 155 cases, 109 participants had CNV, 33 had rare CNV and 22 had one or more rare structural variants that disrupted genes.

The existence of an important genetic contribution to the etiology of schizophrenia is well established from genetic epidemiological studies. The gene of DTNBP1 located on 6p22.3, a high-susceptibility chromosome region of schizophrenia, was highly associated with schizophrenia in Irish high-density pedigrees. DTNBP1, the human ortholog of mouse dysbindin, appears to have a role in neuromuscular synapse formation and maintenance. In the present study, to confirm and extend findings of DTNBP1 in independent samples, researchers investigated seven SNPs within 140-kb length of the gene DTNBP1 in 233 Han Chinese trios. Results showed less heterozygosity in the seven SNPs of DTNBP1 gene compared with the data from a study with Irish high-density pedigrees collected from the relatively homogeneous population of Ireland and Northern Ireland.