OTOG and hearing loss disorder: Vbd is a new recessive ENU mutation of Otog gene characterized by a typical waltzing behaviour and a hearing impairment sharing some common behavioural characteristics either with Otogtm1Prs or twister, the other two allele of Otog. Our results emphasize the importance of detecting and characterizing a new allele of a gene in order to get comprehensive information about the gene function.