Mitochondrial mutations in non-syndromic hearing loss at UAE
Walaa Kamal Eldin Mohamed1, Marc Arnoux2, Thyago H S Cardoso3
1Department of Applied Biology, College of Sciences, University of Sharjah, Sharjah, United Arab Emirates; Laboratory for Immuno Bioengineering Research and Applications, Division of Engineering, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates; Departament de Genètica I de Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Barcelona, Spain.
International Journal of Pediatric Otorhinolaryngology
|September 2, 2020
Summary
Mitochondrial mutations contribute to hereditary hearing loss (HL) in the UAE. Two specific mutations, m.669T>C and m.827A>G in the 12S rRNA gene, were identified in patients with non-syndromic hearing loss.
Area of Science:
- Genetics
- Otolaryngology
- Molecular Biology
Background:
- Hereditary hearing loss (HL) is a global concern, with genetics implicated in over 50% of cases.
- Both nuclear and mitochondrial genes are known causes of hereditary HL.
- Mitochondrial mutations in the MT-RNR1 gene (12S rRNA) have been linked to HL.
Purpose of the Study:
- To investigate the role of mitochondrial 12S rRNA gene mutations in United Arab Emirates (UAE) patients with hearing loss.
- To screen for nuclear gene mutations in patients with identified mitochondrial variants.
Main Methods:
- Conducted mutational screening of the mitochondrial 12S rRNA gene in 74 unrelated UAE patients negative for GJB2 mutations using Sanger and whole-exome sequencing.
- Utilized bioinformatics tools to analyze the pathogenicity of detected DNA variants.
Main Results:
- Identified two known deafness-associated mitochondrial mutations: m.669T>C and m.827A>G in two separate patients.
- Whole-exome sequencing confirmed the absence of nuclear mutations in these patients.
- Mitochondrial mutations accounted for 2.7% of hearing loss in the studied cohort.
Conclusions:
- This study is the first to report mitochondrial DNA (mtDNA) mutations in the UAE.
- The variants m.669T>C and m.827A>G are confirmed as pathogenic causes of hearing loss.
- These variants should be incorporated into the molecular diagnostic protocols for maternally inherited HL in the UAE.