brief report of variants detected in hereditary hearing loss cases in iran over a 3-year period

Background: diagnosis of hereditary hearing loss (hhl) as a heterogeneous disorder is very important especially in countries with high rates of consanguinity where the autosomal recessive pattern of inheritance is prevaent. techniques such as next-generation sequencing, a comprehensive genetic test using targeted genomic enrichment 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 detected 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.