Mutations in the myosin VIIA gene cause a wide phenotypic spectrum , including atypical Usher syndrome

Atypical Usher syndrome can be associated with mutations in the myosin gene MYO7A. Seven families with atypical Usher syndrome phenotypes were investigated for mutations in MYO7A. The results indicate that severity of Usher syndrome may be genetically determined. Usher syndrome is genetically heterogeneous. Atypical Usher syndrome is similar to the third clinical form of Usher syndrome, characterized by progressive hearing loss, retinitis pigmentosa and variable vestibular problems, but they are associated with mutations at different loci. In addition, mutations at MYO7A can be associated with either Usher syndrome type 1 or atypical Usher syndrome.