一例5p15．33微缺失胎儿的产前诊断

Prenatal diagnosis of a fetus with 5p15.33 microdeletion

目的应用单核苷酸多态性微阵列（single nucleotide polymorphism array,SNP-array）技术对1名生育过Prader-Willi综合征患儿的孕妇进行产前诊断。方法应用SNP—array技术对染色体核型正常的胎儿及其父母进行全基因组拷贝数变异（copy number variants，CNVs）筛查，分析芯片检出的所有CNVs，并与其他研究中芯片检出的染色体5p微缺失情况进行对比分析。结果SNP-array检测显示胎儿染色体5p15．33（113576—457213）缺失344kb，缺失片段临床意义不明确；母亲染色体5p15．33相同位置缺失344kb，父亲的芯片检测结果正常，表明胎儿的5p15．33微缺失遗传自表型正常的母亲；孕妇选择继续妊娠，足月顺产一表型正常男婴，随访未发现异常。结论通过该病例基本排除了染色体5p15．33（113576—457213）缺失344kb与猫叫综合征的关系；本研究通过比较分析不同研究中芯片检出的5p微缺失大小、位置及患者表型，为建立5p微缺失表型与基因型的关联性提供了一定的依据。

Objective To screen for genomic copy number variants （CNVs） in a fetus with one sibling affected with Prader-Willi syndrome using single nucleotide polymorphism （SNP） array. Methods The fetus and its parents were subjected to chromosomal karyotyping and SNP array analysis. Results A 5p15.33 microdeletions was identified in the fetus and its phenotypically normal mother with a size of 344 kb （113 576 to 457 213）. The father was normal for both testing. Analysis of literature and CNVs database indicated the above CNV to be variant of unclear significance. The couple decided to continue with the pregnancy and gave birth to a healthy boy at full-term. No abnormalities were found during the follow-up. Conclusion This study may provide further data for the phenotype-genotype correlation of 5p15. 33 microdeletion, which differs from Cri du Chat syndrome.