一例Phelan-McDermid综合征患儿的遗传学分析

摘要

目的 探讨单核苷酸多态性微阵列(single nucleotide polymorphisms array,SNP array)技术在染色体微缺失微重复综合征诊断中的应用价值.方法 应用SNP array对1例常规G显带染色体核型未见异常的Phelan-McDermid综合征患儿行全基因组拷贝数变异(copy number variation,CNV)检测,荧光原位杂交技术(fluorescence in situ hybridization,FISH)对发现的缺失片段进行验证.结果 患儿及其父母的染色体核型分析均未发现异常.全基因组拷贝数检测结果提示患儿染色体22q13.33区存在杂合性缺失,片段大小为2.1 Mb;患儿父母的CNVs检测均未见异常.FISH检测结果证实患儿的22号染色体亚端粒处存在缺失,患儿父亲为4号染色体和22号染色体平衡易位携带者.结论 SNP array技术具有高分辨率和高准确性的优点,对染色体微缺失微重复综合征的检测具有重要临床意义.%Objective To explore the value of single nucleotide polymorphism (SNP) array for molecular diagnosis.Methods A Chinese girl suspected for Phelan-McDermid syndrome was subjected to routine G-banding chromosomal analysis,SNP array,and fluorescence in situ hybridization (FISH) assaying.Results G-banding karyotype analysis has found no abnormality in the girl and her parents.SNP array detected a heterozygous 2.1 Mb deletion at 22q13.33 in the girl,which was confirmed by FISH.The same deletion was not found in either parent.FISH analysis found that her father has carried a balance t(4;22) translocation.Conclusion SNP array has the advantage of high resolution and accuracy,which is valuable for the diagnosis of microdeletion or microduplication syndromes.