Balkan Journal of Medical Genetics

DETECTION OF THE GJB2 MUTATION IN IRANIAN CHILDREN WITH HEARING LOSS TREATED WITH COCHLEAR IMPLANTATION
Peyvandi AA1, Morovvati S2,*, Rabiee HR3, Ranjbar R3, Ajalloueyan M 4, Hassanalifard M4
*Corresponding Author: Saeid Morovvati, Research Center for Human Genetics, Baqiyatallah University of Medical Sciences, Tehran, POB: 19395/5487, Iran; Tel./Fax: +98-21-88620812; E-mail: morovvati@hotmail. com; morovvati@bmsu.ac.ir
page: 19

INTRODUCTION

In genetic assessment of hearing impairment, 46 genes and 81 genetic loci have now been identified and these numbers are increasing [1]. The 35delG mutation on the gap junction protein, b2, 26kDa (GJB2) gene is the most common mutation to be found in children with non syndromic hearing loss and has been identified as the predominant cause of inherited sensorineural deafness [2-7]. The GJB2 gene encodes gap junction channel protein 26 [connexin 26 (Cx26)] which allows direct communication between the cells [8,9]. The Cx26 gene is one member of a family of related gap-junction channel-forming proteins, each of which is commonly named from its molecular weight (Cx26, Cx30, etc.). The genes for 20 different connexin proteins are present in the human genome [9]. Since 1990, genetic assessment of the GJB2 mutation has been performed in children with congenital hearing loss. Now, the American College of Medical Genetics (Bethesda, MD, USA) has presented genetic testing as a routine method for the evaluation of children with congenital hearing loss [10]. Between 27 to 39% of deaf children show abnormalities such as cochlear dysplasia, lateral semicircular canal dysplasia and dilated vestibular aqueduct on imaging studies [computed tomography (CT) and magnetic resonance imaging (MRI)] [11,12]. Imaging studies are expensive and cannot suitably address the cause and prognosis of hearing loss in these children and thus cannot be accepted as the first method of choice. On the other hand, GJB2 testing is simple and can give direct answers to the parents’ concern about the cause and prognosis in their children. Cochlear implantation (CI) is one of the methods of hearing rehabilitation in patients with complete hearing loss and nowadays most children with dominant or recessive congenital hearing loss are candidates for this therapeutic method [13]. The present study had two main purposes: firstly, genetic assessment of children who were referred for CI, and secondly, to determine whether the type of mutation is an important factor in treatment of the studied children.

Number 27 VOL. 27 (2), 2024	Number 27 VOL. 27 (1), 2024
Number 26 Number 26 VOL. 26(2), 2023 All in one	Number 26 VOL. 26(2), 2023
Number 26 VOL. 26, 2023 Supplement	Number 26 VOL. 26(1), 2023
Number 25 VOL. 25(2), 2022	Number 25 VOL. 25 (1), 2022
Number 24 VOL. 24(2), 2021	Number 24 VOL. 24(1), 2021
Number 23 VOL. 23(2), 2020	Number 22 VOL. 22(2), 2019
Number 22 VOL. 22(1), 2019	Number 22 VOL. 22, 2019 Supplement
Number 21 VOL. 21(2), 2018	Number 21 VOL. 21 (1), 2018
Number 21 VOL. 21, 2018 Supplement	Number 20 VOL. 20 (2), 2017
Number 20 VOL. 20 (1), 2017	Number 19 VOL. 19 (2), 2016
Number 19 VOL. 19 (1), 2016	Number 18 VOL. 18 (2), 2015
Number 18 VOL. 18 (1), 2015	Number 17 VOL. 17 (2), 2014
Number 17 VOL. 17 (1), 2014	Number 16 VOL. 16 (2), 2013
Number 16 VOL. 16 (1), 2013	Number 15 VOL. 15 (2), 2012
Number 15 VOL. 15, 2012 Supplement	Number 15 Vol. 15 (1), 2012
Number 14 14 - Vol. 14 (2), 2011	Number 14 The 9th Balkan Congress of Medical Genetics
Number 14 14 - Vol. 14 (1), 2011	Number 13 Vol. 13 (2), 2010
Number 13 Vol.13 (1), 2010	Number 12 Vol.12 (2), 2009
Number 12 Vol.12 (1), 2009	Number 11 Vol.11 (2),2008
Number 11 Vol.11 (1),2008	Number 10 Vol.10 (2), 2007
Number 10 10 (1),2007	Number 9 1&2, 2006
Number 9 3&4, 2006	Number 8 1&2, 2005
Number 8 3&4, 2004	Number 7 1&2, 2004
Number 6 3&4, 2003	Number 6 1&2, 2003
Number 5 3&4, 2002	Number 5 1&2, 2002
Number 4 Vol.3 (4), 2000	Number 4 Vol.2 (4), 1999
Number 4 Vol.1 (4), 1998	Number 4 3&4, 2001
Number 4 1&2, 2001	Number 3 Vol.3 (3), 2000
Number 3 Vol.2 (3), 1999	Number 3 Vol.1 (3), 1998
Number 2 Vol.3(2), 2000	Number 2 Vol.1 (2), 1998
Number 2 Vol.2 (2), 1999	Number 1 Vol.3 (1), 2000
Number 1 Vol.2 (1), 1999	Number 1 Vol.1 (1), 1998

About the journal ::: Editorial ::: Subscription ::: Information for authors ::: Contact