摘要目的:探讨染色体微阵列分析(chromosomal microarray analysis, CMA)技术检测1例无创产前DNA筛查提示18号染色体短臂部分缺失胎儿基因组拷贝数变异的临床价值，为临床遗传咨询提供参考。方法:应用常规染色体G显带技术分析羊水细胞的核型后，CMA技术检测潜在的染色体微缺失或微重复，并对胎儿进行系统超声检查，同时对其父母行相关检测。结果:常规G显带核型分析显示胎儿核型为46，XX，18p+；CMA检测结果显示胎儿18号染色体短臂p11.32-p11.31区段存在约5 Mb缺失，18p11.31-p11.23区域(约2.9 Mb)约6～8个拷贝及18p11.23-p11.22区域(约2.5 Mb)4个拷贝，父母染色体核型分析及芯片检测结果均正常，为新发变异。结论:从无创产前DNA筛查到CMA分子遗传学诊断分析能有效检出染色体微缺失或微重复，明确胎儿基因型与临床表型的对应关系，为染色体微缺失重复综合征的产前诊断提供参考。

abstractsObjective:To assess the value of chromosomal microarray analysis (CMA) to verify a fetus with partial 18p deletion signaled by non-invasive prenatal testing.Methods:G-banding chromosomal karyotyping analysis was carried out on amniotic fluid sample of the fetus and peripheral blood samples from the parents. Amniotic DNA was also subjected to CMA analysis. The fetus was also subjected to systematic ultrasound scan.Results:The fetus was found to have a karyotype of 46, XX, 18p+ . CMA has revealed a 5 Mb deletion at 18p11.32-p11.31, a 2.9 Mb duplication at 18p11.31-p11.23, and a 2.5 Mb duplication at 18p11.23-p11.22. No chromosomal aberration or microdeletion/microduplication was detected in either parent.Conclusion:Non-invasive prenatal testing and CMA are both sensitive for the detection of chromosomal microdeletions and microduplications. CMA can help with clarification of genotype-phenotype correlation and facilitate prenatal diagnosis and genetic counseling for the family.