Professor Christine Petit's team at the Institut Pasteur Genetics of Sensory Defects Unit, in collaboration with INSERM* and the Collège de France, has recently identified mutations in a gene which, contrary to all other mutations of the deafness genes identified to date, do not cause a dysfunction in the auditory sensory organ, the cochlea. Based on the development of a mouse model, the researchers at the Institut Pasteur have shown that in this deafness form, the auditory sensory cells of the cochlea function normally, contrary to the neurons of the auditory pathway. The firing of these neurons is delayed and desynchronised. The representation of auditory stimuli and space that take place along the ascending auditory system is dramatically altered. The gene discovered is the first human gene implicated in hereditary deafness caused by the dysfunction of neurons within the auditory pathway. This research, carried out in collaboration with Paul Avan from the Sensory Biophysics Laboratory at Clermont-Ferrand Faculty of Medicine and 3 laboratories from the EuroHear European consortium, is published in Nature Genetics.
Paris, june 26, 2006
TAs a result of the work carried out by Professor Christine Petit’s team at the Institut Pasteur , we now know that in developed countries most cases of deafness in children are hereditary. Children with profound deafness caused by cochlear disorders can benefit from cochlear implants. These implants substitute for the defective sensory organ as they convert sound into electrical signals delivered by an array of electrodes to the auditory neurons. These neurons transmit the signals to the brain via the central auditory pathways. Nevertheless, in some cases, cochlear implants are a failure; the gene that has recently been discovered may be able to account for such cases.
The molecular diagnosis developed by the researchers will enable clinicians to assess the possible benefits of cochlear implants regarding this form of deafness.
Pioneering the study of hereditary deafness, Professor Christine Petit’s team has identified the genes responsible for some 20 forms of deafness. Their discoveries have also made it possible to elucidate the defective mechanisms accounting these various forms of deafness and opened up the road to understanding the molecular basis of hearing.
* INSERM: Institut National de la Santé et de la Recherche Médicale
"Mutations in the gene encoding pevjakin, a newly discovered protein expressed in the afferent auditory pathway, cause DFNB59 auditory neuropathy in man and mouse" : Nature Genetics , Juin 2006.
Delmaghani S (1), del Castillo FJ (1), Michel V (1), Leibovici M (1), Aghaie A (1), Ron U (2), Van Laer L (3), Ben-Tal N (2), Van Camp G (3), Weil D (1), Langa F (4), Lathrop M (5), Avan P (6) & Petit C (1).
1 Unité de Génétique des Déficits Sensoriels, Institut Pasteur, Inserm UMRS 587, Paris
2 Department of Biochemistry, GeorgeS. Wise Faculty of Life sciences, Tel Aviv University, Israel
3 Department of Medical Genetics, University of Antwerp, Belgique
4 Centre d’Ingénierie Génétique Murine, Institut Pasteur, Paris
5 Centre National de Génotypage, Evry
6 Laboratoire de Biophysique sensorielle, Faculté de Médecine, Clermont-Ferrand
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