Several studies of consanguineous families with members affected by OTFCS have revealed a variety of homozygous PAX1 mutations, including a missense mutation in the paired box region which contributes to reduced DNA-binding capacity, a nonsense mutation predicted to trigger nonsense-mediated decay, and an insertion leading to a truncating frameshift mutation [89,90,91]. The gene discussed is PAX1; the disease is otofaciocervical syndrome 1.