摘要
随着中国二孩政策的全面放开,高危妊娠日益增多,出生缺陷发生率也随之升高。除环境因素外,遗传因素是导致出生缺陷的另一常见原因,尤其是染色体异常。脆性X综合征是一种X染色体连锁不完全显性遗传疾病,发病率仅次于唐氏综合征,常表现为遗传性智力障碍和自闭症等多系统疾病。作为导致智力障碍的第二大原因,其主要由脆性X染色体智力低下基因1中三核苷酸重复序列(CGG)n结构扩展的动态突变,导致其编码的脆性X智能低下蛋白表达缺失或严重减少引起。脆性X综合征的诊断主要依靠临床表现和基因检测,目前尚无有效治疗方法,未来应进一步研究其靶向治疗。
With the implementation of universal two-child policy in China,the high risk pregnancy is increasing by day,and the incidence of birth defect has also increased. Besides the environmental factor,the genetic factor is another common cause of the birth defect,especially the chromosome abnormality. Fragile X syndrome is a X chromosome linked incomplete dominant inherited disease,the incidence of which is second only to Down syndrome,often characterized by multi-systemic diseases including inherited intellectual disability and autism spectrum disorder. As the second reason of intellectual disability,it is mainly caused by the dynamic mutation of trinucleotide repeat sequence( CGG) n expansion in the fragile X mental retardation gene 1,which induces the absent or decreasing expression of fragile X mental retardation protein. The diagnosis of fragile X syndrome is according to the clinical manifestation and genetic test. There is no effective treatment at present. Further research on targeted therapy should be carried out in the future.
引文
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