Brief Report of Variants Detected in Hereditary Hearing Loss Cases in Iran over a 3-Year Period

• Main Authors: Niloofar BAZAZZADEGAN, Raheleh VAZEHAN, Mahsa FADAEE, Zohreh FATTAHI, Ayda ABOLHASSANI, Elham PARSIMEHR, Zahra KALHOR, Mehrshid FARAJI ZONOOZ, Fatemeh AHANGARI, Shima DEHDAHSI, Farshide SAMIEE, Payman JAMALI, Haleh HABIBI, Younes NOURIZADEH, Shokouh MAHDAVI, Maryam BEHESHTIAN, Ariana KARIMINEJAD, Richard JH SMITH, Hossein NAJMABADI
• Format: Article
• Language: English
• Published: Tehran University of Medical Sciences 2019-10-01
• Series: Iranian Journal of Public Health
• Subjects: OtoSCOPE; Hereditary hearing loss; Novel variant; Known variant
• Online Access: https://ijph.tums.ac.ir/index.php/ijph/article/view/18556
• ISSN: 2251-6085; 2251-6093

Background: Diagnosis of hereditary hearing loss (HHL) as a heterogeneous disorder is very important espe-cially in countries with high rates of consanguinity where the autosomal recessive pattern of inheritance is preva-lent. Techniques such as next-generation sequencing, a comprehensive genetic test using targeted genomic en-richment and massively parallel sequencing (TGE + MPS), have made the diagnosis more cost-effective. The aim of this study was to determine HHL variants with comprehensive genetic testing in our country. Methods: Fifty GJB2 negative individuals with HHL were referred to the Kariminejad-Najmabadi Pathology and Genetics Center, Tehran, one of the reference diagnostic genetic laboratories in Iran, during a 3-year period between 2014 and 2017. They were screened with the OtoSCOPE test, the targeted genomic enrichment and massively parallel sequencing (TGE + MPS) platform after a detailed history had been taken along with clinical evaluation. Results: Among 32 out of 50 GJB2 negative patients (64%), 34 known pathogenic and novel variants were de-tected of which 16 (47%) were novel, identified in 10 genes of which the most prevalent were CDH23, MYO7A and MYO15A. Conclusion: These results provide a foundation from which to make appropriate recommendations for the use of comprehensive genetic testing in the evaluation of Iranian patients with hereditary hearing loss.