人类额外小标记染色体的鉴定及其研究价值的探讨  

Identification of human small supernumerary marker chromosomes and discussion of its research valu~

作　　者：偶健[1] 王玮[1] 段程颖[1] 傅文宇[1] 刘一琳[1] 孙健[1] 钟红菱[1] 李红[1] 

机构地区：[1]南京医科大学附属苏州医院、苏州市立医院生殖与遗传中心,江苏省苏州市215002

出　　处：《中华医学遗传学杂志》2013年第1期91-94,共4页Chinese Journal of Medical Genetics

基　　金：苏州市科技计划项目（YJS0937）

摘　　要：目的应用荧光原位杂交（fluorescentinsituhybridization，FISH）结合染色体核型分析了解人类额外小标记染色体（smallsupernumerarymarkerchromosomes，sSMC）的来源，并探讨其发生机理及应用价值。方法对3例羊水染色体核型分析结果显示是47，XN，＋mar的胎儿羊水细胞用两种探针cep-FISH（针对着丝粒）和SubcenM-FISH（针对近着丝粒区域）进行分析。结果病例1的FISH结果为47，XY，＋mar．ishinvdup（22）（q11．1）（D2224＋＋，D14／2221＋，RP11-172D7-），标记染色体完全由异染色质组成，胎儿活产未见异常临床表型。病例2的FISH结果为47，XX，＋mar．ishr（10）（p11．2q11．2）（cepl0＋，RPll-232C13＋，RP11-178ALO＋）[25]／46，XXE10]，标记染色体由着丝粒附近的常染色质和异染色质组成，胎儿活产无异常临床表型。病例3的FISH结果为47，XY，＋mar．ishinvdup（22）（q11．1）（D2224＋，D14／22ZI＋），标记染色体由异染色质组成，胎儿B超有异常但与此标记染色体关系不明。结论由于sSMC来源的多样性，给产前诊断带来了巨大的困难。其鉴定需要在传统的显带核型分析基础上结合FISH或者其他分子技术。其特殊的结构也为基因定位、异染色质研究以及基因治疗等提供了非常有价值的研奔裁体。Objective To identify the origin of human small supernumerary marker chromosomes （sSMCs） using fluorescent in situ hybridization （FISH） combined with G-banding karyotype analysis, and to discuss their mechanisms of formation and research value. Methods Cep-FISH and SubcenM-FISH were used to analyze sSMCs in 3 patients for whom the result of G-banding was 47, XN, ＋ mar. Results The FISH result of case 1 was 47,XY, ＋mar. ish inv dup（22） （qll. 1）（D22Z4＋ ＋ ,D14/22Zl＋, RPll-172D7 --）. The marker has formed exclusively by heterochromatin. A boy was delivered later with no apparent clinical abnormalities. The FISH result of case 2 was 47,XX, ＋mar. ish r（10） （p11. 2q11. 2） （cepl0＋, RPll-232C13＋,RPll-178A10＋）[25]/46,XXE1]. The marker has formed by heterochromatin and nearby centromere. A girl was delivered later with no clinical abnormalities. The FISH result of case 3 was 47 ,XY,＋mar. ish inv dup（22）（q11. 1） （D22Z4＋ ,D14/22Z1＋）. The marker has also formed exclusively by euchromatin. Fetal abnormalities were detected by type B ultrasonography, but were not necessarily related with the marker. Conclusion The diversity of sSMCs has posed a great challenge for prenatal diagnosis. Identification of sSMCs will require combined karyotype analysis and FISH or other molecular techniques such as microarray based comparative genomic hybridization or sequencing. For its specific structure, the sSMCs may also provide a valuable tool for gene mapping, heterochromatin research and gene therapy.

关 键 词：荧光原位杂交 额外小标记染色体 异染色质 常染色质 

分 类 号：R596.1[医药卫生—内科学]