Genetic heterogeneity in Usher syndrome.
Mutations in seven different genes have been associated with Usher syndrome, and an additional four loci have been mapped. The identified genes encode myosin VIIa, harmonin (a PDZ-domain protein), cadherin 23, protocadherin 15, sans (a scaffold-like protein), usherin and clarin. Three clinical types of Usher syndrome have been described: USH1 patients have severe to profound congenital hearing loss, vestibular dysfunction, and retinal degeneration beginning in childhood, those with USH2 have moderate to severe congenital hearing loss, normal vestibular function, and later onset of retinitis pigmentosa, and USH3 patients have progressive hearing loss, which distinguishes them from the other two types. The shaker-1, waltzer, Ames waltzer, and Jackson shaker mice provide murine models for four of the genetic forms of Usher syndrome. Ongoing studies are enabling early diagnosis of Usher syndrome in children who present with hearing loss, thus providing time to prepare for the onset of visual loss.
Keats
Bronya J B
BJ
Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA. bkeats@lsuhsc.edu
Savas
Sevtap
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D048868:Adaptor Proteins, Signal Transducing; D017089:Ankyrin Repeat; D000070585:Cadherin Related Proteins; D015820:Cadherins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D003937:Diagnosis, Differential; D005820:Genetic Testing; D006319:Hearing Loss, Sensorineural / Q000235:genetics*; D006801:Humans; D009419:Nerve Tissue Proteins / Q000235:genetics*; D011498:Protein Precursors / Q000235:genetics*; D012174:Retinitis Pigmentosa / Q000235:genetics*; D013577:Syndrome; D015837:Vestibular Diseases / Q000235:genetics
D048868:Adaptor Proteins, Signal Transducing; C498835:CDHR15, human; D000070585:Cadherin Related Proteins; D015820:Cadherins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D009419:Nerve Tissue Proteins; D011498:Protein Precursors; C118970:USH1C protein, human; C477452:USH1G protein, human