title: Mutational analysis of the mitochondrial 12S rRNA and tRNASer(UCN) genes in Tunisian patients with nonsyndromic hearing loss.
abstract: We explored the mitochondrial 12S rRNA and the tRNASer(UCN) genes in 100 Tunisian families affected with NSHL and in 100 control individuals. We identified the mitochondrial A1555G mutation in one out of these 100 families and not in the 100 control individuals. Members of this family harbouring the A1555G mutation showed phenotypic heterogeneity which could be explained by an eventual nuclear-mitochondrial interaction. So, we have screened three nuclear genes: GJB2, GJB3, and GJB6 but we have not found correlation between the phenotypic heterogeneity and variants detected in these genes. We explored also the entire mitochondrial 12S rRNA and the tRNASer(UCN) genes. We detected five novel polymorphisms: T742C, T794A, A813G, C868T, and C954T, and 12 known polymorphisms in the mitochondrial 12S rRNA gene. None of the 100 families or the 100 controls were found to carry mutations in the tRNASer(UCN) gene. We report here the first mutational screening of the mitochondrial 12S rRNA and the tRNASer(UCN) genes in the Tunisian population which describes the second family harbouring the A1555G mutation in Africa and reveals novel polymorphisms in the mitochondrial 12S rRNA gene.
authors.affiliation: Laboratoire de Génétique Moléculaire Humaine, Faculté de Médecine de Sfax, Tunisia. emna_mkaouar@mail2world.com
authors.forename: Emna
authors.initials: E
authors.lastname: Mkaouar-Rebai
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Tlili
authors.forename: Saber
authors.initials: S
authors.lastname: Masmoudi
authors.forename: Nacim
authors.initials: N
authors.lastname: Louhichi
authors.forename: Ilhem
authors.initials: I
authors.lastname: Charfeddine
authors.forename: Mohamed
authors.initials: M
authors.lastname: Ben Amor
authors.forename: Imed
authors.initials: I
authors.lastname: Lahmar
authors.forename: Nabil
authors.initials: N
authors.lastname: Driss
authors.forename: Mohamed
authors.initials: M
authors.lastname: Drira
authors.forename: Hammadi
authors.initials: H
authors.lastname: Ayadi
authors.forename: Faiza
authors.initials: F
authors.lastname: Fakhfakh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D000072259:Connexin 26; D017630:Connexins; D004252:DNA Mutational Analysis; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing / Q000379:methods*; D034381:Hearing Loss / Q000453:epidemiology* / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D010375:Pedigree; D017354:Point Mutation / Q000235:genetics; D012313:RNA / Q000235:genetics*; D000077278:RNA, Mitochondrial; D012335:RNA, Ribosomal / Q000235:genetics*; D012343:RNA, Transfer / Q000235:genetics*; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D013577:Syndrome; D014416:Tunisia / Q000453:epidemiology
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D005819:Genetic Markers; D000077278:RNA, Mitochondrial; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; D000072259:Connexin 26; D012313:RNA; D012343:RNA, Transfer