A Case of Autosomal Dominant Mental Retardation Type 5 Caused by a Novel Variant of SYNGAP1 Gene
Objective The genetic characteristics of a child with motor retardation and mental retardation without obvious cause were analyzed to strengthen the understanding of autosomal dominant mental retardation type 5(MRD5).Methods A case of a boy who was admitted to the Children's rehabilitation ward of the 980th Hospital of the Joint Logistic Support Force of the Chinese People's Liberation Army in November 2023 due to"unexplained movement and mental retardness"was selected.Clinical data and family history of the child and his family members were collected.Detailed physical examination was conducted on the child,and laboratory and related auxiliary examinations were improved.Complete exome sequencing(WES)and genome copy number Variation sequencing(CNV-seq)for children and their parents.Results The patient is a male,1 year old and 10 months old.His face presents high arched eyebrows,wide eye distance,wide nose bridge,small jaw,low muscle strength and muscle tension of limbs,and backward movement and intellectual development.Abnormal EEG.WES revealed a new mutation in the SYNGAP1 gene,c.1393(exon9)deIC,(p.Leu465)Phefs*9)(NM_006772),family verification showed that both parents were wild type,this new mutation has not been reported at home and abroad.According to the criteria and guidelines for the interpretation of sequence variants published by the American Society for Medical Genetics and Genomics(ACMG)and the American Society for Molecular Pathology,the variant is rated as a pathogenic variant(PVS1+PS2+PM2_Supporting).The disease associated with this gene mutation is MRD5.Conclusion WES was used to diagnose one patient with MRD5,and the discovery of new SYNGAP1 gene variants expanded the pathogenic gene mutation spectrum of MRD5,providing a reliable basis for family genetic counseling.
Intellectual Development DisorderSYNGAP1 GeneVariantMutationFrameshift MutationChild
万方数据
维普
