染色体14q^＋畸形胎儿的产前细胞遗传学研究

Cytogenetic analysis of a complex chromosomal imbalance 14q^＋ in a fetus t-eaturlng mumple congemtal aetects

目的用微阵列比较基因组杂交技术（array-based comparativege nomic hybridization，array-CGH）对1例染色体不平衡易位先天性缺陷胎儿进行检测，分析胎儿基因型和表型的相关性，确定其致病原因，并探讨array-CGH在产前遗传学诊断中的应用价值。方法对超声显示先天性心脏畸形、侧脑室偏宽的1例胎儿进行羊水细胞及其父母外周血细胞G显带核型分析，发现胎儿核型为46，XY，-14，＋der14（q31）？，双亲核型正常；进一步应用array-CGH芯片对胎儿进行全基因组高分辨率扫描分析，确定染色体不平衡的来源、精确位置和大小。结果Array-CGH结果显示胎儿核型为：46，XY，-14，＋der（12；14）（p13；q32．33）del（14）（q32．33→qter）。结论del（14）（q32．33→qter）部分单体可能是胎儿心脏病发病的遗传学原因；array—CGH具有高分辨率和高准确性的优点，适用于产前遗传学诊断，从而为遗传咨询提供更详细的信息。

Objective To analyze chromosomal imbalance in a fetus presenting with congenital heart disease and mild lateral ventriculomegaly, and to investigate the correlation between genotype and phenotype. The etiology of the fetal congenital diseases was determined, and the feasibility of array-based comparative genomic hybridization （array-CGH） application in molecular cytogenetic diagnosis was evaluated. Methods Following conventional G-banding analysis, array-based comparative genomic hybridization （array-CGH） was applied to delineate the precise location and size of genomic imbalance. Results A de novo 46, XY,- 14, ＋ der14 （q31）？ karyotype was identified in the fetus by G-banding analysis. Array-CGH has verified the chromosomal imbalance to be 46, XY,- 14, ＋ der（ 12; 14）（p13; q32.33） del（14）（q32.33→qter）. Conclusion del（14）（q32.33→qter） is probably the predominant cause of the fetal congenital disease. For its high resolution and accuracy, array-CGH has provided a powerful tool for prenatal diagnosis and genetic counseling.