GJB2 mutations in Iranians with autosomal recessive non‐syndromic sensorineural hearing loss

Human Mutation (Impact Factor: 5.14). 05/2002; 19(5):572 - 572. DOI: 10.1002/humu.9033


Hereditary hearing loss (HHL) is an extremely common disorder. About 70% of HHL is non-syndromic, with autosomal recessive forms accounting for ∼85% of the genetic load. Although very heterogeneous, the most common cause of HHL in many different world populations is mutations of GJB2, a gene that encodes the gap junction protein connexin 26 (Cx26). This study investigates the contribution of GJB2 to the autosomal recessive non-syndromic deafness (ARNSD) load in the Iranian population. One hundred sixty eight persons from 83 families were studied. GJB2-related deafness was diagnosed in 9 families (4, 35delG homozygotes; 3, 35delG compound heterozygotes; 1, W24X homozygote; 1, non-35delG compound heterozygote). The carrier frequency of the 35delG allele in this population was ∼1% (1/83). Because the relative frequency of Cx26 mutations is much less than in the other populations, it is possible that mutations in other genes play a major role in ARNSD in Iran. © 2002Wiley-Liss, Inc

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    • "Population Frequency (%) Sample size References Egypt 10.8 111 Snoeckx et al. (2005a) Egypt 10.17 25 Meguid et al. (2008) Egypt 8.7 155 Mohamed et al. (2010) Egypt 13.8 36 This study Palestine 14 48 Shahin et al. (2002) Tunisia 23 95 Trabelsi et al. (2013) Morocco 35.8 81 Abidi et al. (2007) Syria 17 41 Mahayri and Monem (2012) Greek Cypriot 30 30 Neocleous et al. (2006) Iran 4.8 83 Najmabadi et al. (2002) Austria 29 54 Frei et al. (2002) Korea 0 247 Park et al. (2000) Estonia 31 233 Teek et al. (2010) Denmark 4.24 165 Gronskov et al. (2004) Figure 2 564 bp (del (GJB6-D13S1854)) 333 bp (GJB6 exon 1) 460 bp (del (GJB6-D13S1830)) (a) (b) (c) (d) "
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    ABSTRACT: Background Autosomal recessive nonsyndromic hearing loss (ARNSHL) is the most common type of hereditary hearing loss. It is extremely heterogeneous and over 70 loci (known as DFNB) have been identified. The most frequent gene implicated in ARNSHL is GJB2, which is responsible for more than half of the cases. It is located in the DFNB1 locus, which contains the GJB2 and GJB6 genes. Aim of the study The aim of the study was to detect the frequency of mutations in the GJB2 gene and the two most common deletions in the GJB6 gene [Del (GJB6-D13S1830) and del (GJB6-D13S1854)] in 36 Egyptian patients diagnosed with congenital, nonsyndromic hearing loss. Patients and methods Thirty-six patients with congenital, nonsyndromic hearing loss included in the study were sequenced for the exon 2 in GJB2. Multiplex PCR to detect del (GJB6-D13S1830) and del (GJB6-D13S1854) was performed. Results Five patients had the c.35delG mutation in the homozygous form (62.5%) and three patients had the mutation in the heterozygous form (37.5%). No deletions were detected in GJB6 among the studied patients. Conclusion and recommendations The c.35delG mutation is the most common GJB2 mutation among the studied patients. Further studies on other genes involved in the development of ARNSHL are warranted. Cohort study on the Egyptians for detection of the carrier rate is recommended.
    Full-text · Article · Jan 2014
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    • "We did not find the 35delG mutation, which is very common in European and Ashkenazi Jewish population (Estivill et al. 1998; Scott et al. 1998; Roux et al. 2004). It is also the most common GJB2 deafness-causing allele in the rest of Iran (Najmabadi and Cucci 2002). However, the Baluchi population is ethnically distinct from the rest of Iran. "

    Full-text · Article · Sep 2008 · Journal of Genetics
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    • "In the same work the genetic relationship between Greek and Turkish Cypriots is also discussed in the light of historical and genetic data (Deltas, 2004). The Iranian NMDB consists of information on α-and β-thalassemia (Najmabadi et al., 2001, Garshasbi et al., 2003), non-syndromic sensorineural deafness (Najmabadi et al., 2002), hereditary hemochromatosis (Karimi et al., 2004), G6PD deficiency (Mesbah-Namin et al., 2002), phenylketonuria (Vallian et al., 2003), Fragile X syndrome and Y-linked spermatogenic failure (Najmabadi H., personal communication; Fig. 1B, Table 1). For both databases, a list of mutations, their frequencies and the number of chromosomes studied were submitted to the database curators in pre-structured Microsoft Excel sheets. "
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    ABSTRACT: The National Mutation Frequency Databases are continuously updated mutation depositories, which contain extensive information over the described genetic heterogeneity of an ethnic group or population. Here, we report the construction of the Cypriot ( and Iranian National Mutation Frequency Databases (, both derived from an academic effort to provide high quality and up-to-date information on the underlying genetic heterogeneity of inherited disorders in the Cypriot and Iranian populations, respectively. Both databases have been built and maintained online using ETHNOS platform, a specialized software, which provides the means for national mutation database construction and curation. Each database contains brief summaries of the various genetic disorders studied for each population, and an easy-to-use query interface provides, both to specialist as well as to non-specialist users (i.e. patients and their families), instant access to the list and frequencies of the different mutations responsible for the inherited disorders in these populations. Furthermore, numerous links to the respective Online Mendelian Inheritance in Man (OMIM) entries and, when available, to the locus-specific databases fruitfully integrate the databases content into a single Web site. Both databases can serve as valuable online tools for molecular genetic testing of inherited disorders in these populations and could potentially motivate further investigations of yet unknown genetic diseases in the Cypriot and Iranian populations.
    Full-text · Article · Jun 2006 · Human Mutation
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