Myo7ash1-8J homozygous mice circle and bob their heads; heterozygotes are behaviorally normal. Homozygotes of both sexes are viable and fertile (Samples 2000). The hearing of Myo7ash1-8J mutants has not been examined. However, other Myo7a mutations, whose behavioral phenotypes are virtually identical to that of Myo7ash1-J, are associated with deafness.
Mutations in the human ortholog of Myo7a, MYO7A, have been characterized in pedigrees of patients having Usher syndrome type 1 (USH1), an autosomal recessive disorder characterized by profound deafness, vestibular dysfunction and progressive retinitis pigmentosa (Weil et al., 1995; Weston et al., 1996; Adato et al., 1997; Levy et al., 1997; Liu et al., 1998; Espinos et al., 1998; Cuevas et al., 1998, 1999; Janecke et al., 1999). MYO7A mutations have also been identified in patients with autosomal dominant non-syndromic deafness (Liu et al., 1997) and autosomal recessive isolated deafness (Liu et al., 1997; Weil et al., 1997).
