Association Analysis Of HIV Susceptibility Genes And Mutations Screening And CNV Detection Of Autism Susceptibility Genes

PartⅠChemokines and chemokine receptors play a critical role in immune, inflammatory reactions and infectious diseases, including AIDS. HIV-1enters target cells via interaction of virion envelope glycoproteins (gp120) with the CD4molecule and its co-receptors. CCR5and CXCR4are the major co-receptors responsible for HIV-1infection by macrophage-tropic (R5) and T-cell-tropic (X4) HIV-1strains, respectively. During the early stage of HIV-1infection, the major virus phenotype consists of the R5strain. When the X4or dual-tropic (R5/X4) viruses appear, there is a faster CD4+T-lymphocyte depletion and rapid disease progression toward AIDS. The chemokine receptors CCR5, CXCR4and ligand SDF-1play important roles in the entry of HIV-1into a host. Genetic polymorphisms such as CCR5-△32and SDF-13’ A have been reported to be associated with HIV-1susceptibility and the progression of AIDS. As the largest population in the world, the Chinese population is experiencing a rapid increase in HIV prevalence, along with related social and medical problems. The genetic variation of CCR5, CXCR4and SDF-1in Chinese populations is not currently known. The relationship of polymorphisms on these genes with HIV-1infection have not often been investigated in Chinese population except two well-known polymorphisms, CCR5-A32and SDF-13’ A. Considering the noticeable differences in CCR5-A32allele frequency among populations, we aimed to determine the genetic variation in CCR5, CXCR4and SDF-1in Chinese populations. The open reading frames and regulatory regions of CCR5, CXCR4and SDF-1were sequenced in141Chinese individuals from3ethnic groups:Han, Mongol and Uyghur. Moreover,96variants were identified,41of which were newly identified (NI) in Chinese populations.11NI variants were common polymorphisms with an minor allele frequency>5%and one was non-synonymous mutation Trp153Cys. The polymorphism CCR5-△32was found in3Uyghur individuals but was absent in Han and Mongol groups.11putative haplotypes spanning the length of the CCR5gene sequenced region have been identified. Our study revealed the genetic variations in the genes CCR5, CXCR4and SDF-1in Chinese ethnic populations. In the past thirty years, more than50million people worldwide have been infected with human immunodeficiency virus type1(HIV-1), and one third of these individuals have died. Approximately740,000people in China were living with HIV in2009, of which one-third to one-half were injecting drug users (IDUs). Almost one-half of IDUs share needles and syringes in China, which leads to the high HIV-1prevalence more than50%among IDUs in some areas of Yunnan provinces. It was observed that some individuals have remained uninfected despite repeated exposures to HIV-1. Some patients rapidly progress to acquired immunodeficiency syndrome (AIDS) after infection with HIV-1, whereas others have relative immunologic stability. These findings suggest that genetic factors can influence HIV-1susceptibility and the progression of AIDS.Despite repeated exposure to HIV-1, some individuals remain uninfected suggesting that host genetic factors contribute to the susceptibility to HIV-1infection. The genetic studies on HIV-1infection in the Chinese population have mainly focused on the well-known polymorphisms such as CCR5-△32and SDF-13’A, and the sample sizes were relatively small. Given the absence or rarity of CCR5-△32in the Chinese population, it is important to determine the role of other polymorphisms, especially polymorphisms in the regulatory regions of CCR5, CXCR4and SDF-1on HIV-1infection using a large sample. In our study, we sequenced and genotyped15common SNPs in the regulatory regions of CCR5, CXCR4and SDF-1in921male Han Chinese injecting drug users (IDUs), of which263were HIV-1seropositive and658were HIV-1seronegative.15common SNPs with minor allele frequency (MAF)>5%on the regulation regions and coding regions of CCR5, CXCR4and SDF-1were selected for genotyping. rs17540465of SDF-1has a significant difference in case-control association study. The polymorphism rs17540465of SDF-1conferred resistance to HIV-1infection in IDUs. Our findings suggest that SDF-1plays an important role in the susceptibility to HIV-1infection in the Chinese population while CXCR4and CCR5were not associated with HIV infection in Chinese population. Part ⅡAutism spectrum disorder (ASD) is a neurodevelopmental disease with complex genetic and clinical heterogeneity. The core symptoms of ASD are impaired social interactions, deficient communication, restricted interests, and stereotyped activity patterns. The male:female ratio of4:1in ASD suggests the involvement of the X chromosome in the etiology of ASD. Genetic studies show that the neurexin-neuroligin pathway genes contribute susceptibility to ASD, which include cell adhesion molecules NLGN3, NLGN4, NRXN1and scaffolding proteins SHANK2, SHANK3. NLGN proteins expressed highly in brain, are postsynaptic adhesion molecules interacting with presynaptic NRXNs in a calcium-dependent manner. The cytoplasmic tails of neuroligins and neurexins contain a binding site for PDZ domains of scaffolding proteins. The X-linked NLGN3and NLGN4are the first discovered ASD associated genes in this pathway. A frame-shift mutation in esterase domain of the NLGN4protein was identified in two brothers, one with autism and the other one with Asperger syndrome. This finding triggered the genetic and biological studies of neuroligins in ASD. However, only a low frequency of missense/non-sense mutations of NLGN4has been identified in ASD so far. Besides the coding region, the regulatory region and copy number of NLGN4are deserved to be studied in ASD since they may affect the expression level of NLGN4. In this study, we sequenced the regulatory region including the promoter region and5’/3’untranslated regions (UTR) and the entire coding region of NLGN4gene in a cohort of285ASD patients and384controls. We find6SNPs in untranslated regions and the entire coding region of NLGN4gene. Association analysis of6common SNPs in NLGN4did not find significant difference between246male ASD and311male controls.285ASD patients were studied and no missense mutations of NLGN4gene coding region were identified. We also detected the copy number of NLGN4in285ASD cases. No positive results were found in our study, suggesting that NLGN4was not a major disease gene in ASD. Other genes in the neurexin-neuroligin pathway should be investigated in ASD. ASD is a heterogeneous group of neurodevelopmental disorders with a complex inheritance pattern. The prevalence of ASD is about1/100, but closer to1/300for typical autism. Previously, twin and family studies have conclusively described ASD as a genetic neuropsychiatric disorders, with concordance rates of82-92%in monozygotic twins versus1-10%in dizygotic twins, but a recent study finds evidence for a more substantial environmental component. Many rare variants in synaptic proteins have been identified in patients with ASD, little is known about their effects at the synapse and their interactions with other genetic variations. In this study, we also investigated another gene SHANK1in the neurexin-neuroligin pathway. We sequenced the coding region of SHANK1gene in285ASDs and384controls and detected the copy number of SHANK1gene in285ASD cases. Here, following the discovery of6SHANK1missense mutations (A612V, R874H, P1806H, D1926N, G2037D and G2026R) in4patients with autism, and we also identified three SHANK1deletion in three patients and one duplication in one patients with autisms.The identification of mutations in synaptic proteins such as NRXN1, NLGN3and SHANK2/3has demonstrated that a synaptic defect might be at the origin of ASD. Here, we firstly confirm the presence of SHANK1gene missence mutations and CNVs in individuals with ASD. Importantly, we forecasted the protein function of the6missense mutations showing that the variants can potentially impact on the function of the protein, and we detected SHANK1gene showing the allele expression imbalance. These findings showed that SHANK1gene was a major disease gene in our ASD cohort. These results strengthen the role of synaptic genes dysfunction in ASD. A better knowledge of these genetic interactions will be necessary to understand the complex inheritance pattern of ASD.