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Variations in Multiple Syndromic Deafness Genes Mimic Non-syndromic Hearing Loss
G Bademci1, F B Cengiz1, J Foster Ii1
1John P. Hussman Institute for Human Genomics, University of Miami, Miami, 33136, FL, USA.
Scientific Reports
|August 27, 2016
Summary
Genetic analysis revealed that some non-syndromic hearing loss (NSHL) cases harbor variants in syndromic hearing loss (SHL) genes. This finding expands the genetic understanding of hearing impairment and suggests broader genetic testing may be beneficial.
Area of Science:
- Genetics
- Otolaryngology
- Medical Diagnostics
Background:
- Hearing loss exhibits significant genetic heterogeneity, affecting both syndromic (SHL) and non-syndromic (NSHL) forms.
- Identifying causative genetic variants is crucial for accurate diagnosis and potential therapeutic strategies.
Purpose of the Study:
- To investigate the genetic basis of NSHL in patients lacking causative variants in known NSHL genes.
- To explore the potential role of SHL genes in apparently NSHL cases.
Main Methods:
- Whole exome sequencing was performed on 102 unrelated probands with NSHL.
- Detected variants were analyzed in known syndromic hearing loss (SHL) genes.
- Clinical re-evaluation of affected individuals was conducted.
Main Results:
- Five causative variants in SHL genes (SOX10, MITF, PTPN11, CHD7, KMT2D) were identified in 4.9% of probands.
- Subtle syndromic features were noted in some cases, but none met full diagnostic criteria for associated syndromes.
- Pathogenic variants in SHL genes were found in individuals initially evaluated for NSHL.
Conclusions:
- Individuals diagnosed with NSHL may carry pathogenic variants in genes typically associated with SHL.
- This expands the spectrum of genetic causes for hearing loss.
- Consideration of SHL genes in NSHL genetic testing may improve diagnostic yield.
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