Clinical and genetic analysis of a child with developmental and epileptic encephalopathy due to ALG14 gene variants
10.3760/cma.j.cn113694-20240904-00604
- VernacularTitle:ALG14基因变异所致发育性癫痫性脑病患儿临床及遗传学分析
- Author:
Xin LI
1
;
Xin ZHANG
;
Li YANG
;
Shiyan QIU
;
Xixi YU
Author Information
1. 山东第二医科大学附属临沂市人民医院，临沂 276003
- Publication Type:Journal Article
- Keywords:
Child development disorders, pervasive;
Developmental and epileptic encephalopathy;
ALG14 gene;
Mutation, missense;
Whole exome sequencing;
Case repor
- From:
Chinese Journal of Neurology
2025;58(5):528-535
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the clinical phenotypes and genetic features of a child with developmental and epileptic encephalopathy due to compound heterozygous variants in the ALG14 gene, and to improve clinicians′ understanding of the ALG14 gene and its associated disorders. Methods:Clinical data of a child with developmental and epileptic encephalopathy caused by ALG14 gene variants, who visited Linyi People′s Hospital on September 9, 2019, were collected and followed up. Whole exome sequencing (WES) and Sanger sequencing were applied to genetically detect the child and her parents, SWISS-MODEL software was used to perform 3D modeling of proteins for the screened ALG14 gene variants, and the literature was reviewed to summarize the clinical phenotypes and genetic characteristics of patients associated with ALG14 gene. Results:The proband, a 17-year-old female, presented with focal seizures and generalized tonic-clonic seizures, generalized developmental delay, cranial magnetic resonance imaging showing no significant abnormalities, and video-electroencephalogram showing widespread low-amplitude fast rhythms. The WES results showed that the affected child carried compound heterozygous variants c.243A>G (p.Ile81Met) and c.103delG(p.Glu35SerfsTer7) (NM_144988) in the ALG14 gene, and Sanger sequencing validation showed that they were derived from her father and mother with normal clinical phenotype, respectively, and the above loci had not been reported domestically or internationally. 3D modeling revealed that the p.Ile81Met variant resulted in a change in the coding amino acid at position 81, and alteration of the stability and hydrophobicity of the protein, which may affect the protein function; the p.Glu35SerfsTer7 variant resulted in early truncation of the peptide chain, loss of a large number of amino acid fragments, and significant alteration of the protein structure. According to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology, p.Ile81Met was a variant of undetermined clinical significance (PM2+PM3+PP3), and p.Glu35SerfsTer7 was a likely pathogenic variant (PVS1+PM2+PP3). A total of 5 papers were retrieved reporting 13 cases related to ALG14 gene variants (including the present case), 4 cases with pure heterozygous variants, 9 with compound heterozygous variants, involving 11 variant types, all inherited from the parents, of which 9 being missense variants, 1 being shifted code variant, and 1 being intronic deletion variant. The main clinical phenotypes included epileptic seizure (11/13), hypotonia (10/13), craniofacial malformations (8/13), growth disorders (3/13), and behavioral abnormalities (2/13). Conclusions:This article reports the first case of ALG14 gene related developmental and epileptic encephalopathy in a child at home and abroad, characterized by focal seizures, generalized tonic-clonic seizures, and global developmental delay. The compound heterozygous variants c.243A>G (p.Ile81Met) and c.103delG(p.Glu35SerfsTer7) may be the genetic cause of this child, enriching the clinical phenotype and variation spectrum related to this gene.
