| Literature DB >> 35813387 |
Muhammad Imran Naseer1,2, Angham Abdulrhman Abdulkareem1,3, Mahmood Rasool1,2, Hussein Algahtani4, Osama Yousef Muthaffar5, Peter Natesan Pushparaj1,2.
Abstract
Epilepsy is a neurological disorder described as recurrent seizures mild to severe convulsions along with conscious loss. There are many different genetic anomalies or non-genetic conditions that affect the brain and cause epilepsy. The exact cause of epilepsy is unknown so far. In this study, whole-exome sequencing showed a family having novel missense variant c.1603C>T, p. Arg535Cys in exon 10 of Sodium Voltage-Gated Channel Alpha Subunit 1 (SCN1A) gene. Moreover, targeted Sanger sequencing analysis showed c.1212A>G p.Val404Ile in SCN1A gene in 10 unrelated patients and a mutation in Calcium Voltage-Gated Channel Auxiliary Subunit Beta 4 gene where one base pair insertion of "G" c.78_79insG, p.Asp27Glyfs*26 in the exon 3 in three different patients were observed from the cohort of 25 epileptic sporadic cases. The insertion changes the amino acid sequence leading to a frameshift mutation. Here, we have described, for the first time, three novel mutations that may be associated with epilepsy in the Saudi population. The study not only help us to identify the exact cause of genetic variations causing epilepsy whereas but it would also eventually enable us to establish a database to provide a foundation for understanding the critical genomic regions to control epilepsy in Saudi patients.Entities:
Keywords: CACNB4; Epilepsy; SCN1A; Saudi patients; WES
Year: 2022 PMID: 35813387 PMCID: PMC9257097 DOI: 10.3389/fped.2022.919996
Source DB: PubMed Journal: Front Pediatr ISSN: 2296-2360 Impact factor: 3.569
Figure 1Pedigree of the family showing that consanguineous marriages and III-1 mother and IV-1 are the affected members of the family. The * sign represents the samples available for the study.
Figure 2(A) Chromatogram of novel missense variant c.1603C>T, p.Arg535Cys in exon 10 of the SCN1A gene showing that III-1 (mother) and IV-1 (affected girl) are heterozygous having C/T alleles, while all other members are normal having T/T alleles. (B) Protein alignment of different species was done to show the highly conserved amino acid variants p.Arg535Cys SCN1A gene highlighted in all species.
Figure 3(A) Chromatogram of Sanger sequencing showing the c.1212A>G p.Val404Ile in 10 unrelated patients SCN1A gene from the cohort of 25 epileptic sporadic patients. The green oval is showing the change in the base pair in mutant and while type sequence. (B) Protein alignment of different species was done to show the highly conserved amino acid variants p.Val404Ile SCN1A gene highlighted in all species.
Figure 4(A) Chromatogram of Sanger sequencing showing one base pair insertion of “G” nucleotide in exon 3 of CACNB4 gene sequence of c.78_79insG, p.Asp27Glyfs*26 in three different patients from the cohort of 25 epileptic sporadic patients leading to a frameshift mutation. (B) Chromatogram of Sanger sequencing showing wild-type sequence of the CACNB4 gene (obtained from 100 healthy individuals as the control group).
Figure 5(A) Illustration of the predicted wild-type and mutant structures (AF-P35498-F1) of SCN1A and the prediction for the position of p.Arg535Cys. (B) The amino acid Arg at position 535 in the wild-type SCN1A and Cys at position 535 in the mutant SCN1A are shown as space-filling [(Calotte or Corey, Pauling, and Koltun (CPK)] models. (C) Illustration of the wild-type and mutant structures (PDB ID: 7DTD) of SCN1A and the prediction for the position of p.Val404Ile. (D) The amino acid Val at position 404 in the wild-type SCN1A and Ile at position 404 in the mutant SCN1A are shown as space-filling [(Calotte or Corey, Pauling, and Koltun (CPK)] models. (E) The 3D structure of the wild-type CACNB4 structure was designed using the SWISS-MODEL homology modeling platform (27).