Contribution of DFNB1 and DFNB2 loci to neurosensory deafness in affected Tunisian families.

Classical studies have demonstrated genetic heterogeneity for nonsyndromic autosomal recessive congenital neurosensory deafness. The first two DFNB1 and DFNB2 locations were found using two consanguineous Tunisian families respectively from north and south. We tested these loci for cosegregation with deafness in twenty four southern families with nonsyndromic presumed congenital sensorineural deafness and a pedigree structure consistent with autosomal recessive inheritance. Only in our families, did deafness cosegregate with DFNB1. Although our families are from the south, none of them showed linkage to DFNB2.