Genetic composition plays critical roles in the pathogenesis of autism spectrum disorder(ASD).Especially,inherited and de novo intronic variants are often seen in patients with ASD.However,the biological significance ...Genetic composition plays critical roles in the pathogenesis of autism spectrum disorder(ASD).Especially,inherited and de novo intronic variants are often seen in patients with ASD.However,the biological significance of intronic variants is difficult to address.Here,among a Chinese ASD cohort,we identified a recurrent inherited intronic variant in the CHD7 gene,which is specifically enriched in East Asian populations.CHD7 has been implicated in numerous developmental disorders including CHARGE syndrome and ASD.To investigate whether the ASD-associated CHD7 intronic variant affects neural development,we established human embryonic stem cells carrying this variant using CRISPR/Cas9 methods and found that the level of CHD7 mRNA significantly decreased compared to control.Upon differentiation towards the forebrain neuronal lineage,we found that neural cells carrying the CHD7 intronic variant exhibited developmental delay and maturity defects.Importantly,we found that TBR1,a gene also implicated in ASD,was significantly increased in neurons carrying the CHD7 intronic variant,suggesting the intrinsic relevance among ASD genes.Furthermore,the morphological defects found in neurons carrying CHD7 intronic mutations were rescued by knocking down TBR1,indicating that TBR1 may be responsible for the defects in CHD7-related disorders.Finally,the CHD7 intronic variant generated three abnormal forms of transcripts through alternative splicing,which all exhibited loss-of-function in functional assays.Our study provides crucial evidence supporting the notion that the intronic variant of CHD7 is potentially an autism susceptibility site,shedding new light on identifying the functions of intronic variants in genetic studies of autism.展开更多
基金the National Key R&D Program of China(2018YFA0108000)the National Natural Science Foundation of China(31625013,81941405,31771137,31722024,91732302,and 32000726)+4 种基金a Shanghai Brain-Intelligence Project from the Science and Technology Commission of Shanghai Municipality(16JC1420501)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDBS01060200 and XDA16010310)a Shanghai Municipal Science and Technology Major Project(2018SHZDZX05)the Shanghai Pujiang Program(17PJ1410200)the research was supported by the Open Large Infrastructure Research of the Chinese Academy of Sciences.
文摘Genetic composition plays critical roles in the pathogenesis of autism spectrum disorder(ASD).Especially,inherited and de novo intronic variants are often seen in patients with ASD.However,the biological significance of intronic variants is difficult to address.Here,among a Chinese ASD cohort,we identified a recurrent inherited intronic variant in the CHD7 gene,which is specifically enriched in East Asian populations.CHD7 has been implicated in numerous developmental disorders including CHARGE syndrome and ASD.To investigate whether the ASD-associated CHD7 intronic variant affects neural development,we established human embryonic stem cells carrying this variant using CRISPR/Cas9 methods and found that the level of CHD7 mRNA significantly decreased compared to control.Upon differentiation towards the forebrain neuronal lineage,we found that neural cells carrying the CHD7 intronic variant exhibited developmental delay and maturity defects.Importantly,we found that TBR1,a gene also implicated in ASD,was significantly increased in neurons carrying the CHD7 intronic variant,suggesting the intrinsic relevance among ASD genes.Furthermore,the morphological defects found in neurons carrying CHD7 intronic mutations were rescued by knocking down TBR1,indicating that TBR1 may be responsible for the defects in CHD7-related disorders.Finally,the CHD7 intronic variant generated three abnormal forms of transcripts through alternative splicing,which all exhibited loss-of-function in functional assays.Our study provides crucial evidence supporting the notion that the intronic variant of CHD7 is potentially an autism susceptibility site,shedding new light on identifying the functions of intronic variants in genetic studies of autism.
