J Med Genet 1999;36:829-832 ( November )

Cx26 deafness: mutation analysis and clinical variability

A Murgia^a, E Orzan^b, R Polli^a, M Martella^a, C Vinanzi^a, E Leonardi^a, E Arslan^b, F Zacchello^a

^a Department of Paediatrics, University of Padua, Via Giustiniani 3, 35128 Padua, Italy, ^b Service of Audiology and Phonology, University of Padua, Italy

Correspondence to: Dr Murgia.

Revised version received 21 May 1999; Accepted for publication 16 June 1999

Mutations in the gap junction protein connexin 26 (Cx26) gene (GJB2) seem to account for many cases of congenital sensorineural hearing impairment, the reported prevalence being 34-50% in autosomal recessive cases and 10-37% in sporadic cases. The hearing impairment in these patients has been described as severe or profound. We have studied 53 unrelated subjects with congenital non-syndromic sensorineural hearing impairment in order to evaluate the prevalence and type of Cx26 mutations and establish better genotype-phenotype correlation. Mutations in the Cx26 gene were found in 53% of the subjects tested, 35.3% of the autosomal recessive and 60% of the sporadic cases in our series. Three new mutations were identified. The hearing deficit varied from mild to profound even in 35delG homozygotes within the same family. No evidence of progression of the impairment was found.
Alterations of the Cx26 gene account for a large proportion of cases of congenital non-syndromic sensorineural deafness, so it seems appropriate to extend the molecular analysis even to subjects with mild or moderate prelingual hearing impairment of unknown cause.


Keywords: connexin 26; hearing impairment; non-syndromic sensorineural autosomal recessive deafness; mutation detection

---

© 1999 by J Med Genet
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Declau, F., Boudewyns, A., Van den Ende, J., Peeters, A., van den Heyning, P. (2008). Etiologic and Audiologic Evaluations After Universal Neonatal Hearing Screening: Analysis of 170 Referred Neonates. Pediatrics 121: 1119-1126 [Abstract] [Full Text]  
• Morton, C. C., Nance, W. E. (2006). Newborn Hearing Screening -- A Silent Revolution. NEJM 354: 2151-2164 [Full Text]  
• Marlin, S., Feldmann, D., Blons, H., Loundon, N., Rouillon, I., Albert, S., Chauvin, P., Garabedian, E.-N., Couderc, R., Odent, S., Joannard, A., Schmerber, S., Delobel, B., Leman, J., Journel, H., Catros, H., Lemarechal, C., Dollfus, H., Eliot, M.-M., Delaunoy, J.-L., David, A., Calais, C., Drouin-Garraud, V., Obstoy, M.-F., Goizet, C., Duriez, F., Fellmann, F., Helias, J., Vigneron, J., Montaut, B., Matin-Coignard, D., Faivre, L., Baumann, C., Lewin, P., Petit, C., Denoyelle, F. (2005). GJB2 and GJB6 Mutations: Genotypic and Phenotypic Correlations in a Large Cohort of Hearing-Impaired Patients. Arch Otolaryngol Head Neck Surg 131: 481-487 [Abstract] [Full Text]  
• Cryns, K, Orzan, E, Murgia, A, Huygen, P L M, Moreno, F, del Castillo, I, Parker Chamberlin, G, Azaiez, H, Prasad, S, Cucci, R A, Leonardi, E, Snoeckx, R L, Govaerts, P J, Van de Heyning, P H, Van de Heyning, C M, Smith, R J H, Van Camp, G (2004). A genotype-phenotype correlation for GJB2 (connexin 26) deafness. J. Med. Genet. 41: 147-154 [Abstract] [Full Text]  
• Migliosi, V, Modamio-Hoybjor, S, Moreno-Pelayo, M A, Rodriguez-Ballesteros, M, Villamar, M, Telleria, D, Menendez, I, Moreno, F, del Castillo, I (2002). Q829X, a novel mutation in the gene encoding otoferlin (OTOF), is frequently found in Spanish patients with prelingual non-syndromic hearing loss. J. Med. Genet. 39: 502-506 [Full Text]  
• Morton, C. C. (2002). Genetics, genomics and gene discovery in the auditory system. Hum Mol Genet 11: 1229-1240 [Abstract] [Full Text]  
• del Castillo, I., Villamar, M., Moreno-Pelayo, M. A., del Castillo, F. J., Alvarez, A., Telleria, D., Menendez, I., Moreno, F. (2002). A Deletion Involving the Connexin 30 Gene in Nonsyndromic Hearing Impairment. NEJM 346: 243-249 [Abstract] [Full Text]  
• Van Laer, L, Coucke, P, Mueller, R F, Caethoven, G, Flothmann, K, Prasad, S D, Chamberlin, G P, Houseman, M, Taylor, G R, Van de Heyning, C M, Fransen, E, Rowland, J, Cucci, R A, Smith, R J H, Van Camp, G (2001). A common founder for the 35delG GJB2 gene mutation in connexin 26 hearing impairment. J. Med. Genet. 38: 515-518 [Abstract] [Full Text]