Objective To analyze a fetus with heart defects and to assess the recurrence risk for her family.Methods Single nucleotide polymorphism-based arrays (SNP-Array) analysis using Affymetrix Genome-Wide Human SNP CytoHD was performed to analyze the fetus and her parents.Karyotype analysis was also carried out.Results SNP-Array has detected a 14.5 Mb duplication at 9p and a 14.7 Mb deletion at 11q.Karyotype analysis indicated that the fetus's mother has a karyotypeof 46,XX,t(9;11)(p23;q24).Therefore,the fetus has inherited a derivative chromosome 11 derived from the maternal translocation,and her karyotype was 46,XX,der(11)t(9;11)(p23;q24)mat.Conclusion SNP-Array combined with high resolution GTG banding has confirmed that the fetus has a derivative chromosome 11 derived from her mother's balanced translocation,resulting in partial 9p trisomy and partial 11q monosomy.This couple therefore have a high recurrence risk.SNP-Array is capable of detecting small chromosomal imbalance in abnormal fetuses and can pinpoint the breakpoints.It therefore has the advantage for the detection of unbalanced translocation which is difficult to detect with GTG banding,which is important for assessment the recurrence risk for cryptic balanced translocation carriers.%目的 检查1例心脏缺陷的胎儿的病因,为评估其家庭的复发风险提供依据.方法 应用单核苷酸多态微阵列芯片(SNP-Array)对胎儿及其父母进行全基因组DNA扫描分析,同时进行染色体核型分析.结果 高密度SNP-Array芯片检测显示胎儿存在9p末端14.5 Mb的重复合并11q末端14.7Mb的缺失.结合高分辨G显带核型分析,最终确定其母亲核型为46,XX,t(9;11)(p23;q24),胎儿携带一条由母亲9号染色体短臂和11号染色体长臂易位形成的衍生11号染色体,其核型为46,XX,der(11)t(9;11)(p23;q24)mat.结论 SNP-Array结合高分辨G显带核型分析技术确诊了一例胎儿携带的衍生的11号染色体,后者来源于其母亲携带的9p与11q的平衡易位,其家庭再发风险高.SNP-Array能检测出细微的染色体不平衡改变.应用芯片对胎儿进行检测可能提示其父母携带的平衡易位并确定相应的染色体断端,这对隐型易位携带者的检出及复发风险评估有重要价值.
展开▼
