Open AccessA novel variant in UBE3A in a family with multigenerational intellectual disability and developmental delay
Author(s) -
Zhao Xuechao,
Zheng Yuting,
Wang Li,
Wang Yanhong,
Mei Shiyue,
Kong Xiangdong
Publication year - 2022
Publication title -
molecular genetics and genomic medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.765
H-Index - 29
ISSN - 2324-9269
DOI - 10.1002/mgg3.1883
Subject(s) - ube3a , angelman syndrome , sanger sequencing , proband , exome sequencing , intellectual disability , genetics , neurodevelopmental disorder , biology , copy number variation , locus (genetics) , global developmental delay , loss function , bioinformatics , ubiquitin ligase , dna sequencing , gene , phenotype , mutation , ubiquitin , genome
Background Angelman syndrome (AS) is a rare neurodevelopmental disorder and is characterized by severe cognitive disability, motor dysfunction, speech impairment, hyperactivity, and frequent seizures. Although the maternal chromosomal region 15q11.2‐q13 deletion is the most common mechanism of AS, ~10% of individuals with AS are caused by the intragenic variants in the maternally inherited UBE3A , which encodes an E3 ubiquitin ligase. Methods Clinical diagnoses were based on detailed clinical findings. Trio‐based exome sequencing was performed on the proband and her parents to identify the underlying genetic variants. The candidate variants were confirmed by Sanger sequencing following PCR amplification. In silico analyses were conducted to predict the effect of the identified variant on the function of UBE3A protein. Results We identified a novel variant c.2029G>C (p. Gly677Arg) in UBE3A as the most promising candidate. In silico analyses showed that p.Gly677Arg in the UBE3A affects a highly conserved residue. Her mother had the variant at this locus. Sanger sequencing results showed that II‐2, II‐5, II‐7, IV‐1, III‐5, III‐7, III‐8, and III‐9 have the variant c.2029G>C, and all patients inherited maternally variant in UBE3A , while the offsprings of the male carrier were unaffected. Conclusions We identified a novel variant (c.2029G>C) in the UBE3A in a Chinese family with multigenerational intellectual disability and developmental delay. Our findings expanded the genotypic spectrum of AS and provided important information for genetic counseling.