Chen Li-Sha, Xue Dan, Xi Zuo-Ming, Liu Dan-Na, Zou Peng-Shu, Ma Ming, Xia Ying, Chen Xia-Hui, Qiu Guang-Bin, Cao Dong-Hua
Aristogenesis Center, No. 202 Hospital of PLA, Shenyang 110003, PR China.
Genetic disease laboratory, DongChang Maternal and Child Health Hospital, LiaoCheng 252000, PR China.
Gene. 2015 May 25;563(1):72-5. doi: 10.1016/j.gene.2015.03.006. Epub 2015 Mar 6.
We report the case of a patient with a clinical phenotype consistent with Down Syndrome (DS) who has a novel karyotypic abnormality. Karyotypic analyses were performed to investigate the cause of two spontaneous abortions. A balanced translocation between chromosomes 4 and 21 was identified, along with an additional abnormal chromosome 21. We performed high-resolution banding, comparative genomic hybridization (CGH), and FISH studies in both the patient and her mother to define the abnormality and determine its origin. CGH revealed a gain in copy number on the long arm of chromosome 4, spanning at least 24.4 Mb, and a gain in copy number on the long arm of chromosome 21, spanning at least 16.2 Mb. FISH analysis using a chromosome 21 centromere probe and chromosome 4 long arm telomere (4pter) probe confirmed the origin of the marker chromosome. It has been confirmed by the State Key Laboratory of Medical Genetics of China that this is the first reported instance of the karyotype 47,XX,t(4;21)(q31.3;q11.2),+der(21)t(4;21)mat reported in the world.
我们报告了一例临床表型与唐氏综合征（DS）相符但存在新型核型异常的患者病例。进行核型分析以探究两次自然流产的原因。发现了4号和21号染色体之间的平衡易位，以及一条额外的异常21号染色体。我们对患者及其母亲进行了高分辨率显带、比较基因组杂交（CGH）和荧光原位杂交（FISH）研究，以确定异常情况并确定其起源。CGH显示4号染色体长臂上的拷贝数增加，跨度至少为24.4 Mb，21号染色体长臂上的拷贝数也增加，跨度至少为16.2 Mb。使用21号染色体着丝粒探针和4号染色体长臂端粒（4pter）探针进行的FISH分析证实了标记染色体的起源。中国医学遗传学国家重点实验室已证实，这是世界上首次报道的核型47,XX,t(4;21)(q31.3;q11.2),+der(21)t(4;21)mat 。
