一例Helsmoortel-van der Aa综合征患儿的ADNP基因变异分析

Analysis of ADNP gene variant in a child with Helsmoortel-van der Aa syndrome

目的探讨1例特殊面容、智力低下、语言发育迟缓和自闭症谱系障碍患者的分子遗传学病因。方法抽提患者及其家系成员外周血基因组DNA,应用二代测序技术对患者外显子组基因序列进行检测,Sanger测序验证家系可疑致病位点,依据美国医学遗传学与基因组学学会指南对疑似致病性变异位点进行分析。结果全外显子测序提示患者ADNP基因第5外显子存在c.568C>T(p.Q190X)杂合无义变异,导致蛋白质翻译的提前终止,影响蛋白质功能的正常发挥。经Sanger验证患者父母均不携带该变异。结论该患者被诊断为ADNP基因变异导致的Helsmoortel-van der Aa综合征。

Objective To explore the genetic basis for a child manifesting with intellectual disability,language delay and autism spectrum disorder.Methods Genomic DNA was extracted from peripheral blood samples of the child and his family members,and subjected to whole exome sequencing.Candidate variants were verified by Sanger sequencing and interpreted according to the guidelines of the American College of Medical Genetics and Genomics.Results The child was found to harbor a heterozygous c.568C>T(p.Q190X)nonsense variant of the ADNP gene,which was not detected in either parent by Sanger sequencing.Conclusion The clinical and genetic testing both suggested that the child has Helsmoortel-van der Aa syndrome due to ADNP gene mutation,which is extremely rare in China.