摘要
目的回顾性分析17例染色体不平衡易位者的染色体微阵列分析(CMA)结果及其来源,供临床遗传咨询参考。方法回顾性分析2019年1月至2022年1月在成都市妇女儿童中心医院进行CMA检测的7001例样本,2条非同源染色体末端存在1条缺失另1条重复或同时存在重复片段的纳入为不平衡易位者,并通过染色体核型或荧光原位杂交(FISH)检测其亲代来源。结果在7001例样本中共筛选出17例不平衡易位者,17例不平衡易位者CMA结果中3例存在2条非同源染色体的重复片段,染色体总数为47条,多了1条衍生染色体,由重复的两个染色体片段组成;14例存在1条染色体末端的缺失另1条染色体末端的重复,其中10例有核型分析结果提示染色体总数为46条,存在1条衍生染色体,为缺失片段所在染色体,其缺失部分被重复的染色体片段替代。15例进行了来源分析,发现12例双亲之一存在染色体异常,包括11例平衡易位携带者和1例不平衡易位者,在减数分裂过程中形成了不平衡配子;3例双亲染色体正常,为新发变异导致的不平衡易位。结论CMA提示一条染色体末端缺失另一条染色体末端重复或者涉及两条染色体的重复片段时,建议验证双亲是否为平衡易位携带者,有利于遗传咨询指导再生育,评估再发风险。
Objective To retrospectively analyze the results of chromosomal microarray analysis(CMA)and parental origins of unbalanced translocations among 17 patients,so as to provide reference for their genetic counseling.Methods The results of CMA for 7001 samples tested in Chengdu Women and Children′s Central Hospital from January 2019 to January 2022 were retrospectively reviewed.Unbalanced reciprocal translocation was defined as two non-homologous chromosomes with lost and gained segments respectively or both with gained segments,and their parental origins were identified by parental chromosomal karyotyping and/or fluorescence in situ hybridization(FISH).Results In total 17 unbalanced translocations were identified.In three cases,two non-homologous chromosomes both had gained segments,which constituted a derivative chromosome,with the total number of chromosomes being 47.In the remaining 14 cases,there was a terminal deletion on one chromosome and a terminal duplication on the other,10 of which were confirmed by karyotyping,with the total number of chromosomes being 46.In the derivative chromosome,the lost segment was replaced by a gained segment from another chromosome.Among 15 cases undergoing parental origin analysis,12 had paternal or maternal chromosomal abnormalities,including 11 balanced translocations and 1 unbalanced translocation.The unbalanced gametes therefore may form through meiosis.In 3 cases,the parental chromosomes were normal,indicating a de novo origin.Conclusion Discovery of terminal duplication and deletion or gained segments on two non-homologous chromosomes by CMA is suggestive of parental balanced translocation,which can facilitate genetic counseling and assessment the recurrence risk for subsequent pregnancies.
作者
高崇兰
康涵
李兴玉
谢成秀
潘玉纯
Gao Chonglan;Kang Han;Li Xingyu;Xie Chengxiu;Pan Yuchun(Chengdu Women and Children′s Central Hospital,The Affiliated Women and Children's Hospital,School of Medicine,University of Electronic Science and Technology of China,Chengdu,Sichuan 611731,China)
出处
《中华医学遗传学杂志》
CAS
CSCD
2023年第11期1360-1366,共7页
Chinese Journal of Medical Genetics
关键词
不平衡易位
染色体微阵列分析
来源分析
Unbalanced reciprocal translocation
Chromosomal microarray analysis
Parental origin analysis
