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Gene-Polymorphism in Non - Syndromic Hearing Loss: A Systematic Review
Nandhini Balunathan1, Shital S Nair2, Simon Roshan Kumar2
1Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research (DU), Chennai, 600116 India.
Summary
Non-syndromic hearing loss (NSHL) is primarily genetic, with autosomal recessive inheritance being most common. Genetic variations significantly impact auditory system development, influencing hearing from mild to profound levels.
Area of Science:
- Genetics
- Otolaryngology
- Molecular Biology
Background:
- Non-syndromic hearing loss (NSHL) constitutes approximately 70% of hereditary hearing impairment.
- It presents without associated physical or developmental abnormalities.
- NSHL follows autosomal dominant, autosomal recessive, or X-linked inheritance patterns, with autosomal recessive being the most frequent.
Purpose of the Study:
- To systematically review genetic factors contributing to non-syndromic hearing loss.
- To identify prevalent genes and polymorphisms associated with NSHL across diverse populations.
Main Methods:
- A systematic literature search was conducted using PubMed and Google Scholar.
- Inclusion and exclusion criteria were applied to screen 150 articles.
- Twelve selected articles were reviewed for genetic variations in NSHL.
Main Results:
- Genetic alterations are the primary cause of NSHL.
- Specific polymorphisms show population-specific prevalence, such as GJB2 mutations being common in Asian and Caucasian populations but rare in sub-Saharan Africa.
- Genetic factors affecting the cochlea, auditory nerve, and central auditory circuits are implicated.
Conclusions:
- NSHL is predominantly driven by genetic factors, with significant ethnic and geographic variations in gene polymorphism frequencies.
- Understanding these genetic underpinnings is crucial for diagnosing and potentially treating NSHL.
- Further research into population-specific genetic variations is warranted.
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