The Association Study Of PRSS12 Polymorphism With Mental Retardation Of Population In Qinba Mountain Region

Mental retardation (Mental Retardation, MR) also known as the mental handicapped is one of the main mental and neurological disease in the children and young people. The incidence of MR is estimated currently around 1-3%in the population. Mental retardation is a generalized disorder, characterized by subaverage cognitive functioning and deficits in adaptive behaviors. Studies of family,twin and Foster child reveal that genetic factors play an important role in the etiological complex of mental retardation.The Qinba mountain region is one of the higher MR prevalence areas in China. Therefore, it is important to investigate the association between the PRSS12 gene and mental retardation in the Chinese Han population in Qinba mountain area.PRSS12 gene is the first reported extracellular serine protease to be linked to MR. Since its first discovery, series studies showed that NSMR were caused by the autosome PRSS12 genes, and PRSS12 genes expression in the human brain and Prssl2 expression in rodent brain regions, especially in CNS, PRSS12 plays a critical role in learning and memory regions in the relevant hippocampal tissues. PRSS12 genes have been identified as autosomal NSMR genes130 nuclear families of the Chinese Han population including parents and children were sampled in this thesis. According to the mechanism of neural protease regulating the neurotransmission, six commom SNPs in the region of PRSS12 were selected as the genetic markers. Genotypes of six SNPs of PRSS12 were acquired using the PCR-RFLP and molecular genetics technology, and the association relationship between the PRSS12 gene and mental retardation were analyzed according to the Haplotype-based haplotype relation riskand transmission disequilibrium test, using SPSS 17.0, Hapview and UNPHASED softwares. As a result, rs 11098432 and rs793813 selected in the PRSS12 gene appeared association between the PRSS12 gene and mental retardation (P=0.034, P=0.036). At the same time, two commom SNP-SNP haplotype (rs11098432/rs788668,C-C;rs788668/rs7690554,T-A) showed a significant association with MR(P=0.017, P=0.024). In addition,a three-SNPs(A-C-G) and a five-SNPs haplotype(C-C-A-G-C), showed a significant association with MR(P=0.016, P=0.033)(Global P=0.03, P=0.004 ever after Bonferroni corection). Our results demonstrate that the PRSS12 gene abnormal mutation may be a genetic risk factor for MR in Qinba mountain population. Near the region of rs11098432 and rs793813, there may be some mutations that leading to unusual Function.