Zhang Qingping, Bao Xinhua
Department of Pediatrics, the First Hospital of Peking University, Beijing 100034, P.R.China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2015 Jun;32(3):426-9. doi: 10.3760/cma.j.issn.1003-9406.2015.03.028.
Methyl-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.
甲基CpG结合蛋白2基因（MECP2；在线孟德尔人类遗传数据库编号300005）位于X染色体长臂28区。该基因的突变，包括点突变、重复和缺失，可导致严重的神经发育障碍。由整个MECP2基因重复引起的疾病，称为MECP2重复综合征，多见于男性。该综合征的临床表现包括智力低下、肌张力减退、语言发育迟缓、反复感染、进行性痉挛、癫痫、自闭症或具有或不具有面中部发育不全的自闭症特征。大多数患者从未受影响的母亲那里遗传了这种重复，只有少数病例是新发突变。MECP2基因重复的女性通常无症状，因为X染色体失活（XCI）模式偏向。这种基因组重排的推测机制包括叉停滞和模板转换（FoSTeS）以及微同源性介导的断裂诱导复制（MMBIR）。由于这种疾病没有有效的治疗方法，因此为高危家庭提供适当的遗传咨询和产前诊断至关重要。
