EVC基因的复合杂合突变致Ellis-van Creveld综合征的家系遗传学分析:1例报告并文献复习  

Genetic analysis of a family with Ellis-van Creveld syndrome caused by compound heterozygous mutations in the EVC gene:A case report and literature review

作　　者：孙东兰[1] 陈文琪 张晶 彭园园 袁玉凡 王朝希 郭清 张静[1] Sun Dong-Lan;Chen Wen-Qi;Zhang Jing;Peng Yuan-Yuan;Yuan Yu-Fan;Wang Zhao-Xi;Guo Qing;Zhang Jing(Prenatal Diagnostic Center,Shijiazhuang Obstetrics and Gynecology Hospital/Key Laboratory of Maternal and Fetal Medicine of Hebei Province/Shijiazhuang Key Laboratory of Reproductive Health,Shijiazhuang,Hebei 050011,China)

机构地区：[1]石家庄市妇产医院产前诊断分中心/河北省母胎医学重点实验室/石家庄市生殖健康重点实验室,河北石家庄050011

出　　处：《解放军医学杂志》2025年第2期168-175,共8页Medical Journal of Chinese People's Liberation Army

基　　金：河北省卫生健康委医学科学研究课题(20231661);石家庄市科学技术研究与发展计划(221460465)。

摘　　要：目的报告1例超声提示为室间隔缺损、四肢长骨短、多指等疑似Ellis-van Creveld(EVC)综合征,分析其胎儿的家系遗传学,并进行文献复习,以明确其致病原因。方法纳入1例于2021年10月就诊于石家庄市妇产医院产前诊断中心的孕妇,27岁,孕1产0,宫内单胎妊娠,孕17周时超声检测发现胎儿存在多发畸形。将胎儿先证者的羊水细胞及其父母外周血的基因组DNA依次采用染色体核型分析、染色体微阵列分析(CMA)和全外显子组测序(WES)技术进行遗传学检测。对疑似的致病突变进行先证者及父母的Sanger测序验证。继而利用Minigene体外实验对1个剪接变异进行分析。同时检索PubMed等数据库,结合文献报道进行分析。结果本例胎儿的染色体核型分析结果未见异常,CMA未检测出具有临床意义的拷贝数变异(CNV)。WES检测结果显示,胎儿的EVC基因(NM_153717.2)存在两个突变:10号外显子的c.1405G>T(p.E469X)无义突变和13号内含子的c.1886+5G>A剪接突变。家系验证:Sanger测序结果显示父亲为10号外显子c.1405G>T(p.E469X)携带者,母亲为13号内含子c.1886+5G>A携带者,胎儿的复合杂合突变遗传于父母。根据美国医学遗传学与基因组学学会遗传变异分类标准指南,判定c.1405G>T(p.E469X)为疑似致病突变(PVS1+PM2),c.1886+5G>A为疑似致病突变(PM2+PM3_Strong)。Minigene实验结果显示c.1886+5G>A突变造成了13号内含子一段115 bp的滞留,进一步支持了其致病性。复习文献可知,EVC的典型临床表现为四肢短小、肋骨短、轴后多指、指甲和牙齿发育不良、先天性心脏发育缺陷等,通过全外显子组检测发现EVC/EVC2的基因突变为其主要的致病原因,突变类型包括错义突变、大片段的重复/缺失、框内微缺失、无义突变、移码突变、剪接突变等。结论EVC基因的复合杂合突变是本例胎儿的致病原因,该突变的检出扩展了Ellis-van Creveld综合征的基因变异谱。Objective To report the genetic analysis of a family with a fetus suspected of Ellis-van Creveld(EVC)syndrome based on ultrasound findings such as ventricular septal defect(VSD),short long bones in the limbs and polydactyly,and to conduct a literature review to clarify the pathogenic cause.Methods A 27-year-old pregnant woman,who was pregnant for the first time and had no prior deliveries,was admitted to the prenatal diagnosis center of Shijiazhuang Obstetrics and Gynecology Hospital in October 2021.At 17 weeks of gestation,ultrasound detected multiple fetal malformations.The genomic DNA of the fetal proband's amniotic fluid cells and the parents'peripheral blood samples were sequentially subjected to chromosomal karyotype analysis,chromosomal microarray analysis(CMA),and whole exome sequencing(WES).Suspected pathogenic mutations were verified by Sanger sequencing in the proband and its parents.Subsequently,a Minigene in vitro experiment was used to analyze one splicing mutation.Meanwhile,databases such as PubMed were searched,and literature reports were combined for genetic analysis.Results Chromosomal karyotype analysis of the fetus showed no abnormalities,and CMA did not detect any copy number variation(CNV)with clinical significance.WES results revealed two mutations in the EVC gene(NM_153717.2)of the fetus:a nonsense mutation c.1405G>T(p.E469X)in exon 10 and a splicing mutation c.1886+5G>A in intron 13.Family verification using Sanger sequencing showed that the father was a carrier of the c.1405G>T(p.E469X)mutation in exon 10,and the mother was a carrier of the c.1886+5G>A mutation in intron 13.The compound heterozygous mutation of the fetus was inherited from the parents.According to the guidelines of the American College of Medical Genetics and Genomics(ACMG)for classifying genetic variations,c.1405G>T(p.E469X)was classified as likely pathogenic mutation(PVS1+PM2),and c.1886+5G>A was classified as likely pathogenic mutation(PM2+PM3_Strong).The Minigene experiment results showed that the c.1886+5G>A mutatio

关 键 词：骨骼发育不良 Ellis-van Creveld综合征 基因 EVC 全外显子组测序 

分 类 号：R715.5[医药卫生—妇产科学]