微阵列比较基因组杂交技术产前诊断母源性8p部分三体胎儿一例

Prenatal diagnosis of a fetus with partial trisomy 8p resulting from a balanced maternal translocation by array-based comparative genomic hybridization

目的 确定1例主动脉横弓发育不良胎儿的染色体核型,探讨微阵列比较基因组杂交（array based comparative genomic hybridization,array-CGH）技术在分子遗传学及产前诊断中的应用及优越性.方法 应用G显带分析胎儿及其父母的染色体核型,用array-CGH技术明确胎儿衍生染色体片段的来源和区域.结果 G显带染色体分析显示孕妇为46,XX,t（8;16）（p21;q24）平衡易位携带者,胎儿携带46,XX,der（16）t（8;16） （p21;q24）mat的非平衡易位.array-CGH检测证实胎儿衍生染色体片段源自8号染色体短臂,患儿为8p23.3 p21.3三体患儿.结论 胎儿的异常表型（主动脉横弓发育不良）与8p23.3p21.3三体密切相关,父母染色体分析可帮助明确易位性质及来源,从而有利于评估再发风险.array-CGH在染色体异常分析中具有更高的分辨率和准确性.

Objective To determine the karyotype of a fetus with transverse aortic arch hypoplasia,and to investigate the feasibility of array-based comparative genomic hybridization （array-CGH） for molecular genetic diagnosis.Methods G-banding was performed to analyze the karyotypes of the fetus and its parents,and array CGH was applied to identify the chromosomal abnormality of the fetus.Results G-banding analysis revealed that the pregnant woman has carried a balanced translocation 46,XX,t（8;16） （p21;q24）,while the fetus has carried an unbalanced translocation 46,XX,der（16）t（8;16）（p21;q24）mat.Array-CGH analysis suggested that the derivative chromosomal fragment has originated from 8p with breakpoints in 8p23.3 p21.3.Conclusion Trisomy 8p23.3-p21.3 may have predisposed to transverse aortic arch hypoplasia in the fetus.Parental karyotype analysis could help to characterize the translocation and evaluate the recurrent risk.Compared with routine karyotype analysis,aCGH has a higher resolution and greater accuracy for mapping chromosomal aberrations.