title: Mutational analyses of the FMR1 gene in Chinese pediatric population of fragile x suspects: low tolerance for point mutation.
abstract: CGG repeat expansion is the most common cause of fragile X syndrome. Numerous efforts have been made to identify novel mutations in patients with intellectual disability, developmental delay, and/or autism. To evaluate the mutational spectrum in the at-risk Chinese population, 60 pediatric patients presenting fragile X traits but normal-sized CGG repeats were sequenced for all 17 exons and regulatory regions in FMR1. A c.879A>C mutation, reported to alter a neighboring splicing, was detected in a severely retarded male and his normal mother. However, the exon junction appears unaffected. A 237-kb deletion covering the entire FMR1 was identified to cause moderate intellectual disability and marked hyperactivity in an 8-year-old boy. The 5' and 3' breakpoints were buried in the surrounding long interspersed and short interspersed elements, respectively. In general, missense mutations do not commonly cause fragile X syndrome, whereas deletions should be considered with caution in patient referrals presenting with developmental delay and/or ordinary retardation.
authors: State Key Laboratory of Medical Genetics, Xiangya School of Medicine, Central South University, Changsha, 410078, Hunan, China.
authors: Shiyu
authors: S
authors: Luo
authors: State Key Laboratory of Medical Genetics, Xiangya School of Medicine, Central South University, Changsha, 410078, Hunan, China.
authors: Wen
authors: W
authors: Huang
authors: State Key Laboratory of Medical Genetics, Xiangya School of Medicine, Central South University, Changsha, 410078, Hunan, China.
authors: Qiuping
authors: Q
authors: Xia
authors: State Key Laboratory of Medical Genetics, Xiangya School of Medicine, Central South University, Changsha, 410078, Hunan, China.
authors: Qian
authors: Q
authors: Du
authors: State Key Laboratory of Medical Genetics, Xiangya School of Medicine, Central South University, Changsha, 410078, Hunan, China duanranhui@sklmg.edu.cn.
authors: Lingqian
authors: L
authors: Wu
authors: State Key Laboratory of Medical Genetics, Xiangya School of Medicine, Central South University, Changsha, 410078, Hunan, China wulingqian@sklmg.edu.cn.
authors: Ranhui
authors: R
authors: Duan
mesh_terms: D002648:Child; D002681:China; D005091:Exons; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D005600:Fragile X Syndrome / Q000235:genetics*; D006801:Humans; D006948:Hyperkinesis / Q000235:genetics*; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D017354:Point Mutation
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1
keywords:  FMR1 mutation; Chinese pediatrics; deletion