一例心脏缺陷胎儿染色体1p36．3微缺失的产前诊断

Prenatal diagnosis of 1p36.3 microdeletion in a fetus with complex heart defect

目的对1例心脏缺陷胎儿进行细胞遗传学诊断，明确其病因，为再生育复发风险评估及产前诊断提供依据。方法应用单核苷酸多态微阵列芯片（single nucleotide polymorphism—based arrays，SNP—array）对胎儿及其父母行全基因组DNA扫描分析，结合G显带核型分析及荧光原位杂交（fluorescence in situ hybridization，FIsH）验证胎儿染色体1p36．3微缺失的来源。结果高密度SNP—array芯片检测显示胎儿在1p36．33p36．23存在6．9Mb的微缺失，G显带核型分析和FISH检测提示其父亲核型为46，XY，t（1；14）（p36．3；p12），胎儿携带一条由父亲1P末端和14p末端平衡易位形成的1号衍生染色体，核型为46，XY，der（1）t（1；14）（p36．3；p12）pat。结论SNP—array结合G显带和FISH技术有助于发现染色体末端隐匿性易位、微缺失或微重复，提高诊断准确率，对复发风险的评估有重要价值。

Objective To analyze a fetus presenting with complex heart defect and assess the recurrence risk. Methods Conventional karyotyping, fluorescence in situ hybridization （FISH） and single nucleotide polymorphism-based array （SNP-array） were used to analyze the fetus and his parents. Results SNP-Array has detected a 6.9 Mb microdeletion at lp36.33-p36.23 in the fetus. Chromosomal and FISH analyses indicated that the father of the fetus had a karyotype of 46,XY,t（1;14）（p36.3;p12）, and that the fetus has inherited an abnormal chromosome 1 derived from the paternal translocation. Conclusion SNP- Array combined with GTG banding and FISH can help to detect cryptic translocation, microdeletion or microduplication of chromosomes and is valuable to assess the recurrence risk for the affected family.