부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.heares.2005.08.001 Byline: BouchaA[macron]b Gazzaz (a)(b), Dominique Weil (d), LeA[macron]la RaA[macron]s (c), Omar Akhyat (e), Houssine Azeddoug (b), Sellama Nadifi (a) Keywords: Deafness; ARNSHL; Sporadic; GJB2 and GJB6; Morocco Abbreviations: ARNSHL, autosomal recessive non syndromic hearing loss; GJB, gap junction (protein); [beta], subgroup; DFNB, deafness, autosomal recessive; CX, connexin (protein); ACRS-PCR, artificial created restriction site - polymerase chain reaction; DGGE, denaturing gradient gel electrophoresis; GJA, gap junction (protein); [alpha], subgroup; NSHL, non syndromic hearing loss Abstract: Deafness is a heterogeneous disorder showing different pattern of inheritance and involving a multitude of different genes. Mutations in the gene, GJB2 Gap junction type 1), encoding the gap junction protein connexin-26 on chromosome 13q11 may be responsible for up 50% of autosomal recessive nonsyndromic hearing loss cases (ARNSHL), and for 15-30% of sporadic cases. However, a large proportion (10-42%) of patients with GJB2 has only one GJB2 mutant allele. Recent reports have suggested that a 342-kb deletion truncating the GJB6 gene (encoding connexin-30), was associated with ARNSHL through either homozygous deletion of Cx30, or digenic inheritance of a Cx30 deletion and a Cx26 mutation in trans. Because mutations in Connexin-26 (Cx26) play an important role in ARNSHL and that distribution pattern of GJB2 variants differs considerably among ethnic groups, our objective was to find out the significance of Cx26 mutations in Moroccan families who had hereditary and sporadic deafness. One hundred and sixteen families with congenital deafness (including 38 multiplex families, and 78 families with sporadic cases) were included. Results show that the prevalence of the 35delG mutation is 31.58% in the family cases and 20.51% in the sporadic cases. Further screening for other GJB2 variants demonstrated the absence of other mutations; none of these families had mutations in exon 1 of GJB2 or the 342-kb deletion of GJB6. Thus, screening of the 35delG in the GJB2 gene should facilitate routinely used diagnostic for genetic counselling in Morocco. Author Affiliation: (a) Laboratoire de Genetique Medicale, Faculte de Medecine et de Pharmacie, Casablanca, Maroc (b) Laboratoire de Biologie Moleculaire, Faculte des Sciences Ain Chock, Casablanca, Maroc (c) Departement d'ophtalmologie, CHU Ibn Rochd, Casablanca, Maroc (d) Unite de genetique des deficits sensoriels, Institut Pasteur Paris, France (e) Laboratoire de Biologie Moleculaire, Faculte des Sciences Ibn Zohr, Agadir, Maroc Article History: Received 27 April 2005; Accepted 4 August 2005