一例主动脉狭窄伴拇指缺如患儿的遗传学诊断

Genetic diagnosis of a child with aortic stenosis and thumb aplasia

目的分析1例主动脉狭窄伴拇指缺如患儿的发病机制，为遗传咨询提供依据。方法用常规G显带分析患儿及其父母的外周血染色体核型，用微阵列比较基因组杂交（array comparative genomic hybridization，aCGH）技术对患儿及其父母进行染色体片段重复／缺失的分析。结果G显带分析结果显示患儿及其父母染色体核型未见异常。aCGH检测结果显示患儿2q22．3-q23．3区存在5．86Mb的杂合缺失，其父母未检测到染色体微重复／微缺失。结论患儿2q22．3-q23．3缺失为新发突变，诊断为2q23．1微缺失综合征，MBD5基因可能是该综合征的关键基因。

Objective To analyze the molecular mechanism and prognosis of a child with aortic stenosis and thumb aplasia. Methods The karotypes of the child and his parents were analyzed with routine G-banding. Their genomic DNA was also analyzed with array comparative genomic hybridization （aCGH） for chromosomal duplications/deletions. Results No karyotypic abnormality was detected at cytogenetic level for the child and his parents, aCGH identified a de novo 5.86 Mb deletion at 2q22.3-q23.3 in the child. Conclusion The child was diagnosed with 2q23.1 microdeletion syndrome. MBD5 may be the key gene for the 2q23.1 microdeletion syndrome.