摘要甲基化CPG结合蛋白2基因(methyl-CpG-binding protein 2 gene,MECP2;OMIM:300005)位于Xq28.该基因的点突变、重复或缺失突变都会造成严重的神经系统疾病.MECP2基因重复突变导致的疾病称为MECP2重复综合征,该综合征多发于男性,主要临床表现包括智能发育迟滞、肌张力低下、语言发育落后、反复感染、癫痫发作、孤独症及孤独症样表现,并可有面部发育不良.患者重复的MECP2基因多由携带此突变的母亲遗传而来,少数为新生突变.女性携带者无临床表现的原因可能为X染色体非随机失活.MECP2基因重复的分子机制可能是由复制叉停滞以及模板交换导致的基因重排,或微同源序列介导的断裂点诱导复制所致.该疾病目前无有效的治疗方法,因而对高危家庭提供产前咨询及产前诊断非常必要.

abstractsMethyl-CpG-binding protein 2 gene (MECP2;OMIM 300005) is located at chromosome Xq28.Mutations of the gene including point mutation,duplication and deletion can lead to severe neurodevelopmental disorders.The disease caused by duplication of the entire MECP2 gene,named as MECP2 duplication syndrome,is mostly seen in males.The clinical manifestation of this syndrome include mental retardation,hypotonia,poor speech development,recurrent infection,progressive spasticity,epilepsy,autism or autistic features with or without midface hypoplasia.Most patients have inherited the duplication from their unaffected mothers,with only a few cases having de novo mutation.Females with duplicated MECP2 gene are typically asymptomatic because of a skewed X chromosome inactivation (XCI) pattern.Proposed mechanisms of this genomic rearrangement include fork stalling and template switching (FoSTeS) and microhomology mediated break-induced replication (MMBIR).Since no effective treatment is available for this disease,proper genetic counseling and prenatal diagnosis for the high risk families are crucial.