Analysis of the 5' region of the canine PAX3 gene and exclusion as a candidate for Dalmatian deafness.

The causative mutation in a gene related to hearing loss in Dalmatians has been elusive. Because of its role in melanocyte migration and differentiation as integral component of the inner ear, we hypothesized that the canine PAX3 (paired box homeotic gene 3) gene could be a candidate for Dalmatian deafness. Therefore, we isolated the canine PAX3 gene and searched for causative mutations within the coding region of important regulatory domains of PAX3. However, no mutations were identified when comparing the DNA sequences of healthy and affected dogs. These results were confirmed by a two-point linkage analysis in 203 Dalmatians transmitting deafness. Our data clearly show that the canine PAX3 gene can be excluded as candidate for Dalmatian deafness.