[The mutation 35delG of the gene of the connexin 26 is a frequent cause of autosomal-recessive non-syndromic hearing loss in Morocco].
Mutations of the connexin 26 gene, GJB2, are the most common cause of non syndromic autosomal-recessive hearing loss. One of the GJB2 mutations, the 35delG, is recurrent in European and Mediterranean populations with allelic frequency of at least 70% in patients with hearing loss caused by GJB2 impairment.


OBJECTIVE
To determine the prevalence of the 35delG mutation in non-syndromic autosomal-recessive deafness in Morocco.


METHODS
We looked for the 35delG mutation among 25 non-related Moroccan children suffering from an autosomal recessive hearing loss. A screening for GJB2 mutations, and then a search for GJB6 deletions were carried out among patients who do not bear the 35delG.


RESULTS
Twelve patients were homozygous for the 35delG mutation. This mutation was responsible for almost half of the hearing loss among our patients (48%). There was no other GJB2 or GJB6 mutation among 13 patients.


CONCLUSIONS
This study underlines the advantages of a systematic search for this mutation among deaf children when environmental causes are considered irrelevant. The identification of this genetic anomaly signs the etiologic diagnosis of deafness, which allows a relevant genetic advice, and a better treatment of patients.
Ratbi
I
I
Département de Génétique Médicale, Institut National d'Hygiène, Rabat, Maroc. ilhamratbi@yahoo.fr
Hajji
S
S
Ouldim
K
K
Aboussair
N
N
Feldmann
D
D
Sefiani
A
A
D000293:Adolescent; D002648:Child; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D005260:Female; D034381:Hearing Loss / Q000235:genetics*; D006801:Humans; D008297:Male; D009018:Morocco; D009154:Mutation; D016133:Polymerase Chain Reaction; D017384:Sequence Deletion
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26