环状染色体遗传学效应及临床表型分析

Genetic effect and clinical phenotype analysis of ring chromosome

目的探讨环状染色体在产前和产后标本中的发生率,分析其临床表型及遗传学特征。方法回顾性分析2012—2023年因各种产前诊断指征就诊的47162例妊娠孕妇,经腹羊水穿刺术并染色体核型分析;86607例就诊的1个月至48岁不等的患者行外周血染色体核型分析。结果产前样本中共检出环状染色体20例,发生率约为4.24/10000,其中r(X)占比最多约37%,其次是r(18)、r(Y)、r(4)、r(13)等。产后外周血样本中发现36例环状染色体,发生率约为4.16/10000,其中r(X)占比74%,其次是r(Y)以及r(21)。结论环状染色体会导致成人不孕不育、儿童生长发育及智力异常等,其临床表型复杂多样,产前诊断缺乏特异性指标,增加了临床诊断的难度。G显带核型分析技术和染色体微阵列比较基因组杂交检测(CMA)技术在环状染色体诊断上各有优势,联合应用才能明确诊断环状染色体。

Objective To investigate the incidence of ring chromosome in prenatal and postnatal samples,and analyze its clinical phenotype and genetic characteristics.Methods A retrospective analysis was conducted on 47162 pregnant women who visited due to various prenatal diagnostic indications between 2012 and 2023,underwent amniocentesis and chromosomal karyotype analysis;and 86607 patients aged between 1 month and 48 years who underwent peripheral blood chromosomal karyotype analysis.Results A total of 20 ring chromosomes were detected in prenatal samples,with an incidence rate of approximately 4.24/10000,among which r(X)accounted for about 37%,followed by r(18),r(Y),r(4),r(13),etc.In postnatal peripheral blood samples,36 cases of ring chromosomes were found,with an incidence rate of approximately 4.16/10000,where r(X)accounted for 74%,followed by r(Y)and r(21).Conclusion Ring chromosomes can lead to infertility in adults,growth and developmental abnormalities in children,and intellectual disabilities.The clinical phenotypes are diverse and complex,lacking specific indicators for prenatal diagnosis,which increases the difficulty of clinical diagnosis.G-banding karyotype analysis and CMA technology each have their advantages in the diagnosis of ring chromosomes,and a combined application is necessary for a definitive diagnosis of ring chromosomes.