Positive association between PTN polymorphisms and schizophrenia in Northeast Chinese Han population

As a severely and highly heritable psychotic disorder, schizophrenia has become a serious public health problem in modern society. Pleiotrophin (PTN) is a secreted cell cytokine associated with the extracellular matrix and acts as a growth factor. PTN is mainly expressed in neuroectodermal and mesodermal tissues, indicating its effect in neuron migration and epithelium-mesenchyme interactions. Whereas PTN is associated with some neurodegenerative diseases and has modulating effects on them. In this study, we aimed to investigate the association between PTN polymorphisms and schizophrenia in an independent case-control sample-set including 738 schizophrenia patients and 1085 healthy controls. Of the 13 selected single nucleotide polymorphisms (SNPs), five showed significant differences in allele or/and genotype frequencies between patients and controls: rs3959914 (genotype: χ = 11.5217, P = 0.0032); rs11765480 (genotype: χ = 10.6620, P = 0.0049); rs1473355 (genotype: χ = 8.3902, P = 0.0151); rs322246 (allele: χ = 5.5954, P = 0.0180); rs322240 (genotype: χ = 8.8429, P = 0.0121; allele: χ = 8.7802, P = 0.0031). The haplotype analysis of the selected SNPs showed different haplotype frequencies for one block (rs322240, rs322246) between cases and controls (global: χ = 9.0290, P = 0.0110; A-G: χ = 8.985, P = 0.0027; C-A: χ = 5.814, P = 0.0159). Our present results indicate PTN as a susceptibility gene for schizophrenia.