母源性1p36缺失综合征和3p26.3p25.2重复1例胎儿的产前诊断

Prenatal diagnosis of a fetus with 1p36 deletion syndrome and 3p26.3p25.2 duplication

目的探讨1例1p36缺失综合征和3p26.3p25.2重复胎儿的特征。方法选取2022年2月22日于临沂市人民医院确诊的1例胎儿作为研究对象,收集其临床资料,并对其进行染色体核型分析、荧光原位杂交(FISH)检测和染色体微阵列分析(CMA)。结果孕24周超声提示胎儿存在室间隔缺损、单脐动脉、左侧脑室轻度增宽(12 mm)。孕妇染色体核型为46,XX,t(1;3)(p36.22;p25.2),FISH检测结果为46,XX.ish t(1;3)(3pter+,1qter+;1pter+,3qter+);胎儿羊水细胞G显带核型为46,X?,add(1)(p36);CMA显示胎儿染色体1p36.33p36.22区存在9.0 Mb缺失,3p26.3p25.2区存在12.6 Mb重复,结合孕妇的染色体核型,最终确定胎儿的分子细胞核型为46,X?,der(1)t(1;3)(p36.22;p25.2)mat.arr[hg19]1p36.33p36.22(849467_9882666)×1,3p26.3p25.2(61892_12699607)×3。其中1p36.33p36.22缺失片段与1p36缺失综合征相关。结论胎儿的1p36.33p36.22缺失和3p26.3p25.2重复来源于孕妇1号和3号染色体平衡易位所产生的不平衡配子,可能导致室间隔缺损、单脐动脉、侧脑室增宽等表型。

Objective To explore the characteristics of a fetus with chromosome 1p36 deletion syndrome and 3p26.3p25.2 duplication.Methods A pregnant woman who had attended the Genetic Counseling Clinic of Linyi People′s Hospital on February 22,2022 and her fetus were selected as the study subjects.Clinical data were collected.Chromosomal karyotyping,fluorescence in situ hybridization(FISH)and chromosomal microarray analysis(CMA)were carried out for the prenatal diagnosis.ResultUltrasonography at 24th gestational week revealed that the fetus had ventricular septal defect,single umbilical artery,and slight widening of left lateral ventricle(12 mm).The woman was found to have a karyotype of 46,XX,t(1;3)(p36.22;p25.2),and the result of FISH was t(1;3)(3pter+,1qter+;1pter+,3qter+).The fetus was found to have a karyotype of 46,X?,add(1)(p36),and CMA confirmed that it has a 9.0 Mb deletion at 1p36.33p36.22 and a 12.6 Mb duplication at 3p26.3p25.2.Combining the maternal karyotype,the molecular karyotype of the fetus was determined as 46,X?,der(1)t(1;3)(p36.22;p25.2)mat.arr[hg19]1p36.33p36.22(849467_9882666)×1,3p26.3p25.2(61892_12699607)×3,with the former known to be associated with 1p36 deletion syndrome.Conclusion The fetus was diagnosed with 1p36 deletion syndrome,and its 1p36.33p36.22 deletion and 3p26.3p25.2 duplication had both derived from the balanced translocation carried by its mother.