Association Study Between Autism And CORO2B And Mutation Screening For PAK2Gene In Autism From Chinese Population

Characterized by a combination of abnormalities in communication and social interaction as well as restricted and repetitive behaviors, autism is a neurodevelopmental syndrome commonly referred to as autism spectrum disorder （ASD）. ASD is etiologically heterogeneous which typically presents prior to age three years, affect boys4times more often than girls. Recent epidemiological survey shows that the incidence rate of ASD has been up to1/50. In recent years, a number of mutations and susceptibility genes have been identified by karyotype analysis, linkage analysis, GWAS, Genome-wide CNV analysis. Most of these genes are related to neurodevelopment, neuronal plasticity, synaptic connections, neural circuit.Chapter1:Association Study between Autism and CORO2B in Chinese PopulationBackgrounds:CORO2B is predominantly expressed in the brain. CORO2B may play specific roles in the reorganization of neuronal actin structure, a change that has been implicated in both cell motility and growth cone advance. Copy number variations analysis the children with autism in our study find a15q23-24deletion which contains CLN6, CORO2B and SEP8, etc.31genes. GWAS （Genome Wide Association Study） show that the SNP （single nucleotide polymorphism） of CORO2B are associated with autism.Aims:The purpose of this experiment is to verify whether CORO2B genes are associated with autism in a new batch of samples, to explore the correlationship between CORO2B and autism in Chinese population.Methods:Selection of the TagSNP （rsl465997） which are associated with autism in the correlation linkage disequilibrium regions, entered UCSC （http://genome.ucsc.edu/） to find rs1465997of CORO2B gene. Regarded the nucleotide sequence of both sides of rs1465997as the target fragment, we used primer3（http://frodo.wi.mit.edu/primer3/） to design primer. The rs1465997was amplified by PCA and direct sequencing using the Sanger method. Results were analyzed using DNAStar/SeqMan software to know allele combinations of270autism trios. We used plink to make Hardy-Weinberg Equilibrium （HWE） and transmission disequilibrium test （TDT）.Results:Genotyping of270core pedigrees in this SNP accord with Mendelian inheritance. The MAF （Minor Allele Frequency） of rs1465997is0.24. The genotype of the patients accord with Hardy-Weinberg Equilibrium （p=0.25）. The results of TDT （transmission disequilibrium test） are not accordance with statistical significance （P=0.0522）, and the OR （odds ratio, OR=0.76） of TDT is not supported the previous result. Conclusions:The results failed to validate the results of previous GWAS. Our results do not support CORO2B gene are associated with autism in this batch of samples of Chinese Population. Chapter2:Mutation Screening for PAK2Gene in Autism from Chinese PopulationBackgrounds:In human, p21protein-activated kinase2（PAK2） gene has only one isoform that is NM₀02577. PAK2gene has14exons, which coding region is1.575Kb. PAK1and PAK3are linked to intellectual disability and Alzheimer’s disease. Chromosome3q29deletion syndrome （#609425） had delayed psychomotor development with mild to moderate mental retardation and/or learning disabilities with speech delay and autism. Chromosome3q29duplication syndrome （#611936） had mild to moderate mental retardation and minor dysmorphic features.3q29contains PAK2, DLG1, SENP5, etc.22genes.Aims:In this study, we screening for PAK2gene mutations in autism from Chinese population, to explore the correlationship between PAK2gene mutations and autism in Chinese population. Methods:Entered UCSC （http://genome.ucsc.edu/） to find PAK2gene and5’UTR area base sequence. Regarded PAK2gene coding region and the5’UTR as the target fragment, we used primer3（http://frodo.wi.mit.edu/primer3/） to design primer. The primer was amplified by PCA and direct sequencing using the Sanger method. Results were analyzed using DNAStar/SeqMan software to find mutation sites.Results:By PCR amplification of exons and5’UTR on312children with autism, we find2mutations in the5’UTR that are C.-191C>T and c.-167G>T. And c.-167G>T is SNP. In the exons, we find4mutations that are c.315A>G、c.630T>C、c.1176G>A and C.1272C>T,which all are synonymous mutation. Mutations nearby exons are4mutations that are c.289-3t>a, c.576+14g>a, c.1154-21₁154-20instgttt and c.1350+8g>c. Mutations of c.289-3t>a, c.1154-21₁154-20instgttt and c,1350+8g>c are SNP.Conclusions:In this study, we did not find mutations which can change the amino acid in autism from Chinese population. This study shows that PAK2gene coding region mutations aren’t associated with autism in Chinese population.