【摘要】 目的不明原因智力低下和孤独症谱系障碍儿童脆性X综合征FMR1基因筛查结果分析。方法选择不明原因智力低下和孤独症谱系障碍患儿35例,采用常规G显带染色体核型分析患儿染色体畸变情况,CNV-seq技术分析染色体拷贝数变异,PCR结合毛细管电泳法分析FMR1基因5’非编码区的CGG重复序列数目。结果 35例患儿中核型异常者2例,CNVs异常者4例,1例患儿的FMR1基因5’非编码区的CGG重复序列数目大于200,为全突变型脆性X综合征,此患儿临床表现为语言发育滞后,智力低下等,患儿母亲为前突变携带者。结论对智力低下和孤独症谱系障碍人群进行脆性X综合征的基因筛查分析,是对其他遗传学检测方法的重要补充,对于明确发病频率,致病原因和后续的遗传咨询、产前诊断具有重要的参考应用价值。更多还原

【Abstract】 Objective To analyze of screening and phenotype for fragile X syndrome in intellectually disabled population of unknown causes and children with autistic disorder. Methods The study included 35 patients(Male 31, Female 4) with intellectually disabled population of unknown causes or autistic disorder referred to our hospital from November 2018 to November 2019. Cytogenetic analysis by G-banding staining was performed to evaluate chromosome anomalies in the patients. Meanwhile, CNV-Seq analysis was conducted to determine the status of chromosome copy numbers variations in the patients. In addition, real-time PCR analysis followed with capillary electrophoresis was performed to detect the CGG trinucleotide repeats in 5’UTR of FMR1 gene. Results Two patients were found with karyotype anomalies in the total 35 cases. Four patients were detected with abnormal CNVs results. One patient, with full mutation, was found with over 200 CGG trinucleotide repeats in 5’UTR of FMR1 gene. The patient presented with delayed language development and mental retardation. Moreover, pedigree analysis revealed that the proband’s mother was a premutation carrier. Conclusion Conducting genetic screening for fragile X syndrome in the intellectually disabled population of unknown causes and children with autistic disorder is an importantly supplemental method as comparing with other genetic analysis methods. It is necessary for the morbidity investigation in the intellectually disabled population of unknown causes and children with autistic disorder. It also benefits for the earlier identification, intervention, genetic consulting and prenatal diagnosis for the patients with fragile X syndrome.更多还原