Clinical characteristics and genetic analysis of a case of autosomal dominant mental retardation-42 caused by GNB1 gene mutation
10.3760/cma.j.cn113694-20230827-00088
- VernacularTitle:GNB1基因变异所致常染色体显性遗传性智力低下42型1例临床特点及基因分析
- Author:
Daoqi MEI
1
;
Yuan WANG
;
Junfang SUO
;
Miao LIU
;
Ang MA
;
Yiran ZHAO
;
Qiuping HE
Author Information
1. 郑州大学附属儿童医院 河南省儿童医院 郑州儿童医院东区神经内科，郑州 450018
- Keywords:
GNB1 gene;
Mutation, missense;
Developmental disabilities;
Autosomal dominant mental retardation-42;
Child;
Case reports
- From:
Chinese Journal of Neurology
2024;57(5):473-480
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To summarize the clinical phenotype and genetic characteristics of a case of autosomal dominant mental retardation-42 (MRD42) caused by GNB1 gene mutation. Methods:The clinical and genetic data of a case of MRD42 caused by a GNB1 gene missense mutation diagnosed in the Department of Neurology, Children′s Hospital Affiliated to Zhengzhou University in March 2023 were retrospectively analyzed. The child was followed-up, the child′s data were summarized, and related literature was reviewed. Results:The patient is a 6-month-old female infant, who was admitted to hospital because of "developmental delay for 3 months, intermittent convulsions for 1 month". The clinical manifestations included generalized tonic-clonic seizures, focal seizures, intellectual disability, delayed language and motor development. Long-term video electroencephalogram showed slightly slower background activity, bilateral occipital spike and wave discharges, multispike and wave complexes during sleep. Three focal onset seizures were captured. Cranial magnetic resonance imaging suggested that the subarachnoid space of the bilateral frontotemporal areas was slightly wide. Chromosome karyotype and copy number variation analysis showed no abnormality. The results of whole exon sequencing showed a de novo heterozygous missense mutation in the GNB1 gene [NM_002074:c.155(exon5)G>A;p.Arg52Gln], which had not been reported. The seizure was effectively controlled by function rehabilitation training and anti-epileptic drug therapy. Conclusions:MRD42 is a rare autosomal dominant disorder caused by mutation in the GNB1 gene. The clinical manifestations include infantile-onset seizures, mental retardation, speech and motor development delay, etc. The de novo heterozygous missense mutation in the GNB1 gene c.155G>A(p.Arg52Gln) is the genetic cause of the proband.
