There are three main common deafness susceptibility genes: 1. Mutations in the GJB2 gene, which can lead to severe sensorineural deafness or delayed hearing loss. 2. Mutations in the SLC26A4 gene, which can lead to large vestibular aqueduct syndrome, manifesting as progressive and fluctuating hearing loss. 3, Mitochondrial 12SrRNA gene mutation, which can lead to drug-sensitive deafness.