Identification of a locus on chromosome 7q31, DFNB14, responsible for prelingual sensorineural non-syndromic deafness

In our efforts to identify new loci responsible for non-syndromic autosomal recessive forms of deafness, DFNB loci, we have pursued the analysis of large consanguineous affected families living in geographically isolated areas. Here, we report on the study of a Lebanese family affected with a prelingual profound sensorineural isolated form of deafness. Segregation analysis resulted in a linkage with locus D7S554 to locus D7S2459 on 7q31, with a maximum lod score of 6.3. The causative gene was mapped to a 15 cM interval extending from D7S527 to D7S3074 (on the telomeric side). The distal limit of this interval could be located between D7S496 and D7S3074 which are the closest polymorphic loci flanking the gene underlying Pendred syndrome (PDS) on the centromeric and on the telomeric sides, respectively. To eliminate PDS as a candidate gene, its 21 exons were sequenced. No mutation was detected. This study therefore reports the identification of a novel locus, DFNB14, on chromosome 7q31, in a position proximal to PDS.