Mahbobeh Koohiyan1,2, Mohammad Reza Noori-Daloii3, Morteza Hashemzadeh-Chaleshtori4, Mansoor Salehi1, Hamidreza Abtahi5, Mohammad Amin Tabatabaiefar6,7. 1. Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. 2. Cancer Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran. 3. Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 4. Cellular and Molecular Research Center, Basic Health Research Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran. 5. Department of Otolaryngology, Al-Zahra Hospital, Isfahan University of Medical Sciences, Isfahan, Iran. 6. Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran, tabatabaiefar@med.mui.ac.ir. 7. Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Noncommunicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran, tabatabaiefar@med.mui.ac.ir.
Abstract
BACKGROUND AND OBJECTIVES: Hereditary hearing loss (HL) can originate from mutations in one of many genes involved in the complex process of hearing. CABP2 mutations have been reported to cause moderate HL. Here, we report the whole exome sequencing (WES) of a proband presenting with prelingual, severe HL in an Iranian family. METHODS: A comprehensive family history was obtained, and clinical evaluations and pedigree analysis were performed in the family with 2 affected members. After excluding mutations in the GJB2 gene and 7 other most common autosomal recessive nonsyndromic HL (ARNSHL) genes via Sanger sequencing and genetic linkage analysis in the family, WES was utilized to find the possible etiology of the disease. RESULTS: WES results showed a novel rare variant (c.311G>A) in the CABP2gene.This missense variant in the exon 4 of the CABP2gene meets the criteria of being pathogenic according to the American College of Medical Genetics and Genomics (ACMG) interpretation guidelines. CONCLUSIONS: Up to now, 3 mutations have been reported for the CABP2gene to cause moderate ARNSHL in different populations. Our results show that CABP2variantsalso cause severe ARNSHL, adding CABP2to the growing list of genes that exhibit phenotypic heterogeneity. Expanding our understanding of the mutational spectrum of HL genes is an important step in providing the correct clinical molecular interpretation and diagnosis for patients.
BACKGROUND AND OBJECTIVES: Hereditary hearing loss (HL) can originate from mutations in one of many genes involved in the complex process of hearing. CABP2 mutations have been reported to cause moderate HL. Here, we report the whole exome sequencing (WES) of a proband presenting with prelingual, severe HL in an Iranian family. METHODS: A comprehensive family history was obtained, and clinical evaluations and pedigree analysis were performed in the family with 2 affected members. After excluding mutations in the GJB2 gene and 7 other most common autosomal recessive nonsyndromic HL (ARNSHL) genes via Sanger sequencing and genetic linkage analysis in the family, WES was utilized to find the possible etiology of the disease. RESULTS: WES results showed a novel rare variant (c.311G>A) in the CABP2gene.This missense variant in the exon 4 of the CABP2gene meets the criteria of being pathogenic according to the American College of Medical Genetics and Genomics (ACMG) interpretation guidelines. CONCLUSIONS: Up to now, 3 mutations have been reported for the CABP2gene to cause moderate ARNSHL in different populations. Our results show that CABP2variantsalso cause severe ARNSHL, adding CABP2to the growing list of genes that exhibit phenotypic heterogeneity. Expanding our understanding of the mutational spectrum of HL genes is an important step in providing the correct clinical molecular interpretation and diagnosis for patients.
Keywords:
American College of Medical Genetics and Genomics guideline; Autosomal recessive nonsyndromic hearing loss; CABP2; Genetic linkage analysis; Whole exome sequencing
Authors: Inger Norlyk Sheyanth; Allan Thomas Højland; Henrik Okkels; Ihab Lolas; Christian Thorup; Michael Bjørn Petersen Journal: Mol Genet Genomic Med Date: 2021-03-05 Impact factor: 2.183