title: Usher syndrome: clinical findings and gene localization studies.
abstract: The issue of genetic heterogeneity is a critical problem in the localization of the gene(s) for Usher syndrome. Based on the data obtained on families studied to date, the differences between type I and type II Usher syndrome appear quite distinct with regard to auditory and vestibular function. Although the majority of families can be confidently diagnosed as typical type I or type II, clinical investigations revealed four families with findings that did not fit into either of the two more common subtypes. These findings emphasize the critical importance of an in-depth clinical analysis concomitant with the linkage investigation to assure accurate subtyping of Usher syndrome. Based on an analysis of only those families with definite type I or type II Usher syndrome, approximately 17% of the genome can be excluded as a potential site of the gene for type I, and 14% can be excluded as the site for the type II gene. This study will continue until the Usher gene(s) is successfully localized.
authors.affiliation: Boys Town National Institute of Communication Disorders in Children, Omaha, NE 68131.
authors.forename: W J
authors.initials: WJ
authors.lastname: Kimberling
authors.forename: C G
authors.initials: CG
authors.lastname: Möller
authors.forename: S L
authors.initials: SL
authors.lastname: Davenport
authors.forename: G
authors.initials: G
authors.lastname: Lund
authors.forename: T J
authors.initials: TJ
authors.lastname: Grissom
authors.forename: I
authors.initials: I
authors.lastname: Priluck
authors.forename: V
authors.initials: V
authors.lastname: White
authors.forename: M D
authors.initials: MD
authors.lastname: Weston
authors.forename: K
authors.initials: K
authors.lastname: Biscone-Halterman
authors.forename: P E
authors.initials: PE
authors.lastname: Brookhouser
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004247:DNA / Q000032:analysis; D005260:Female; D008040:Genetic Linkage; D006319:Hearing Loss, Sensorineural / Q000235:genetics*; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D012150:Polymorphism, Restriction Fragment Length; D012174:Retinitis Pigmentosa / Q000235:genetics*; D013577:Syndrome; D014724:Vestibular Function Tests
chemical_list: D004247:DNA