一例罕见小片段缺失所致的Smith-Magenis综合征患儿的遗传学诊断

Genetic diagnosis of a case of Smith-Magenis syndrome due to a rare small-scale deletion

目的对一例罕见的小片段缺失的Smith-Magenis综合征患儿进行遗传学诊断。方法采集患儿的病史及临床资料,通过染色体核型分析、多重连接探针扩增(multiplex ligation-dependent probe amplification,MLPA)和拷贝数变异测序(copy number variation sequencing,CNV-seq)技术对患儿及其父母进行检测。结果患儿染色体核型分析未见异常,MLPA及CNV-Seq检测结果发现其染色体17p11.2区内存在1.22 Mb的缺失与0.3 Mb的重复,其父母均未见异常。结论确诊患儿携带17p11.2区1.22 Mb的新发缺失,属于罕见的小片段SMS缺失。

Objective To report on a case of Smith-Magenis syndrome(SMS)due to a rare small-scale deletion.Methods Medical history and clinical data of the patient were collected.The child and his parents were subjected to chromosome karyotyping analysis,multiplex ligation-dependent probe amplification(MLPA)and copy number variation sequencing(CNV-seq).Results The child was found to have a normal karyotype.MLPA and CNV-seq detection showed that he has harbored a 1.22 Mb deletion and a 0.3 Mb duplication in the 17p11.2 region.Neither of his parents was found to have similar deletion or duplication.Conclusion The child was diagnosed with SMS due to a rare 1.22 Mb deletion in the 17p11.2 region,which is among the smallest deletions associated with this syndrome.