en Genetics & Disease Genetics & Disease Case Report Case Report <p style="text-align: left">Hearing loss (HL) is the most common sensory defect. Various genetic as well as environmental factors have been shown to contribute in it. More than 100 loci have been recognized to cause autosomal recessive nonsyndromic hearing loss (ARNSHL). Here, we report a 6-year old female patient with bilateral pre-lingual HL in whom a mutation has been identified in <em>TRIOBP</em> gene (c.6362C>T, S2121L). <em>In silico</em> analysis has shown that this variant is possibly pathogenic. Although several mutations have been detected in this gene in various populations, this is the first report identifying <em>TRIOBP</em> mutation in Iranian population. Consequently, the results of the present study may be of importance in genetic counseling.</p> Hearing loss, TRIOBP, mutation 245 247 http://ijmcmed.org/browse.php?a_code=A-10-572-2&slc_lang=en&sid=1 Majid Fardaei mfardaei@sums.ac.ir 10031947532846006039 10031947532846006039 No Department of Medical Genetics, Shiraz University of Medical Sciences, Shiraz, Iran. Shaghayegh Sarrafzadeh soudehgh@yahoo.co.uk 10031947532846006040 10031947532846006040 No Department of Medical Genetics, Shahid Beheshti University of Medical sciences, Tehran, Iran. Soudeh Ghafouri-Fard s.ghafourifard@sbmu.ac.ir 10031947532846006041 10031947532846006041 Yes Department of Medical Genetics, Shahid Beheshti University of Medical sciences, Tehran, Iran. Mohammad Miryounesi miryounesi@sbmu.ac.ir 10031947532846006042 10031947532846006042 No Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.