临床儿科杂志 ›› 2024, Vol. 42 ›› Issue (11): 948-954.doi: 10.12372/jcp.2024.23e1018

• 论著 • 上一篇    下一篇

DDX3X基因变异致X连锁智力障碍3例临床分析及康复随访

夏秦1, 顾琴1, 陈婷2, 张何威1, 霍洪亮1, 曹徐君1, 王巍巍1, 吉永春1()   

  1. 1.苏州大学附属儿童医院 康复科,(江苏苏州 215000)
    2.苏州大学附属儿童医院 内分泌科(江苏苏州 215000)
  • 收稿日期:2023-10-24 出版日期:2024-11-15 发布日期:2024-11-08
  • 通讯作者: 吉永春 E-mail:277965661@qq.com
  • 基金资助:
    苏州市科教兴卫青年科技项目(KJXW2021027)

Clinical analysis and follow-up of rehabilitation training of X-linked intellectual disability caused by DDX3X gene variation: a report of three cases

XIA Qin1, GU Qin1, CHEN Ting2, ZHANG Hewei1, HUO Hongliang1, CAO Xujun1, WANG Weiwei1, JI Yongchun1()   

  1. 1. Department of Rehabilitation, Children's Hospital of Soochow University, Suzhou 215000, Jiangsu, China
    2. Department of Endocrinology, Children's Hospital of Soochow University, Suzhou 215000, Jiangsu, China
  • Received:2023-10-24 Online:2024-11-15 Published:2024-11-08
  • Contact: JI Yongchun E-mail:277965661@qq.com

摘要:

目的 总结DDX3X基因变异导致X连锁智力障碍(XLID)患儿的临床特征及基因变异特点。方法 回顾性分析2018年1月至2021年4月在康复科就诊的3例因DDX3X基因变异致XLID患儿的基因检测结果及临床表型,长期随访其康复训练效果。结果 例1为8个月23天男孩,例2为6个月女孩,例3为1岁6个月女孩。3例患儿首次就诊均表现为全面发育迟缓,特殊面容及肌张力障碍。全外显子测序发现例1为DDX3X基因c.1025+3A>C(p?)剪切突变,其母亲该位点为杂合子状态,父亲为野生型,根据美国医学遗传学与基因组学学会(ACMG)指南,该变异为临床意义未明性变异。经RT-PCR及Sanger验证后,该变异可引起内含子10部分保留及外显子10部分跳跃,提示该变异可能是导致基因功能异常的候选位点,该位点未经报道。例2为c.1535-1536delAT(p.H512Rfs*5)缺失突变,其父母该位点均为野生型,根据ACMG指南,该变异为新发致病性变异。例3为在DDX3X基因7号内含子区域发现一处c.679+2T>G剪切突变,其父母该位点均为野生型,该变异为新发致病性变异。结论 本研究发现3个新的国内首次报道的DDX3X基因变异位点,其中1例剪切突变经验证为候选位点;丰富了DDX3X基因变异谱,为患儿的临床诊断和遗传咨询提供了依据。

关键词: DDX3X基因, X连锁智力障碍, 遗传学分析

Abstract:

Objective To summarize the clinical and genetic characteristics of X-linked intellectual disability (XLID) caused by DDX3X gene variation. Methods The clinical data of 3 children with XLID caused by DDX3X gene variation who were treated in the rehabilitation department from January 2018 to April 2021 were retrospectively analyzed. Results Case 1 was a boy aged 8 months and 23 days, case 2 was a girl aged 6 months, and case 3 was a girl aged 1 year and 6 months. All the three patients presented with total growth retardation, special facial features and muscle dystonia at the first visit. The whole exome sequencing showed that case 1 had a splicing mutation of C. 1025+3A>C (p?) in the DDX3X gene. The site was heterozygous in the mother and wild-type in the father. According to the American College of Medical Genetics and Genomics (ACMG) guidelines, this variant was of unknown clinical significance. After RT-PCR and Sanger verification, it was found that this mutation could cause partial retention of intron 10 and partial skipping of exon 10, suggesting that the mutation might be a candidate site for abnormal gene function, and this site has not been reported. Patient 2 had a deletion mutation of c.1535-1536delAT (p.H512Rfs*5), which was wild-type in both of her parents. According to ACMG guidelines, this mutation was a de novo pathogenic mutation. In child 3, a splicing mutation of c.679+2T>G was found in the intron 7 region of DDX3X gene. Both of her parents had wild type at this site, and this mutation was a de novo pathogenic mutation. Conclusions In this study, three new DDX3X gene mutation sites were reported for the first time in China and one of them was verified as a candidate site for splicing mutation. Above findings have enriched the mutation spectrum of DDX3X gene and provided a basis for clinical diagnosis and genetic counseling.

Key words: DDX3X gene, X-linked intellectual disability, genetic analysis