环状染色体患儿12例的临床表型及遗传学分析

Clinical phenotype and genetic analysis of twelve children with ring chromosomes

目的探讨环状染色体在儿童生长发育期的发生率, 分析其临床表型和遗传学特征。方法选取2015年1月至2021年8月因生长发育异常就诊的儿童7 574例, 采集其外周血样进行G显带染色体核型分析。结果在7 574例患儿中, 共检出12例环状染色体, 检出率为0.16%, 具体包括1例r(6)、2例r(9)、2例r(13)、1例r(14)、2例r(15)、1例r(21)以及3例r(X)。12例患儿均存在不同程度的表型异常, 包括生长发育迟缓、智力低下、肢体畸形、先天性心脏病等。在具有相同断裂位点的2例r(9)患儿和2例r(15)患儿中, 各有1例仅表现为生长发育迟缓, 其余2例则合并r(9)有特殊面容、复杂先天性心脏病等。携带r(X)的患儿具有Turner综合征的部分表现。结论环状染色体是导致儿童生长发育及智力异常的重要原因, 其临床表型复杂多样, 临床医师应仔细采集这类患儿的病史, 并尽早完善染色体检查以明确诊断。

1ObjectiveeTo explore the prevalence and clinical manifestations of ring chromosomes among children featuring abnormal development.Methods From January 2015 to August 2021,7574 children referred for abnormal development were selected,and their peripheral blood samples were subjected to G-banded chromosomal karyotyping analysis.ResultsTwelve cases of ring chromosomes were detected,which have yielded a prevalence of 0.16%and included 1 r(6),2 r(9),1 r(13),1 r(14),2 r(15),1 r(21)and 3 r(X)among 7574 children.The children had various clinical manifestations including growth and mental retardation,limb malformation,and congenital heart disease.For two children with r(9)and two with r(15)with similar breakpoints,one child with r(9)and one with r(15)only had growth retardation,whilst another with r(9)and another with r(15)also had peculiar facies and complex congenital heart disease.The r(X)has featured some manifestations of Turner syndrome.Conclusion Ring chromosomes are among the common causes for severe growth and mental retardation in children with diverse clinical phenotypes.Clinicians should pay attention to those with developmental anomalies and use chromosomal analysis to elucidate their genetic etiology.