Denne siden ble automatisk oversatt og nøyaktigheten av oversettelsen er ikke garantert. Vennligst referer til engelsk versjon for en kildetekst.

Study of Usher Syndromes, Type 1 and Type 2

3. mars 2008 oppdatert av: National Eye Institute (NEI)

Usher Syndrome - Clinical and Molecular Studies

The purpose of this investigation is to gain additional knowledge about what causes type 1 and type 2 Usher syndrome-inherited diseases that can cause balance problems and impaired hearing and vision-and to develop better diagnostic tests. Patients with type 1 Usher syndrome usually are deaf from birth and have speech and balance problems. Patients with type 2 disease generally are hearing impaired but have no balance problems. All patients develop eye problems that cause difficulty seeing in the dark.

The development of newer and more sophisticated diagnostic tests may detect subtle differences in signs and symptoms that allow more accurate distinction between the two types of Usher syndrome. This study will use these tests to classify these syndromes and eventually identify the genes responsible for them.

Study participants will have a medical and family history taken and a family tree constructed. They will undergo a thorough eye examination, including special tests of color vision, field of vision, and ability to see in the dark. An electroretinogram will be done to measure the function of cells in the retina, and a procedure called fluorescein angiography will be done to look at and photograph the blood vessels in the retina. Special hearing and balance tests will also done. Hearing tests include physical examination of the ears and wearing earphones while listening to tones. Balance and coordination tests require tasks such as walking in a straight line and standing in the dark with eyes closed. A caloric stimulation test will also be done, in which a small amount of water is irrigated into the ear canal. For gene studies, blood samples will be collected from patients and all available family members.

Studieoversikt

Status

Fullført

Forhold

Detaljert beskrivelse

The Usher Syndromes (USH), characterized by autosomal recessive inheritance, are genotypically distinct diseases which share specific phenotypic characteristics. Affected individuals have congenital neurosensory hearing impairment of variable severity and a progressive pigmentary retinal degeneration commonly referred to as retinitis pigmentosa. Interfamilial differences in USH patients are greater than intrafamilial differences and investigators have proposed at least two distinct phenotype types; Usher Syndrome type 1 (USH 1) and Usher Syndrome type 2 (USH 2) (Fishman 1983). Patients with USH 1 are profoundly deaf from birth, have unintelligible speech and absent vestibular function. Nightblindness is apparent in the 1st or 2nd decade accompanied by an extinguished electroretinogram (ERG) and profound loss of visual field. Patients with USH 2 can have moderate to severe hearing loss and normal vestibular function. Nightblindness occurs in the 2nd or 3rd decade, there is variable field loss and variable response by the ERG (Fishman 1983).

Heterogeneity has been verified by linkage studies and at least three USH 1 loci and two USH 2 loci are known (Kimberling et al 1990; Lewis et al 1990; Kaplan et al 1992; Smith et al 1992a.)

With increasingly sophisticated clinical testing, subtle differences may permit a more accurate distinction between the two USH phenotypes. The purpose of this study is to classify as accurately as possible these patients' clinical features by careful audiologic, vestibular, psychophysical and electrodiagnostic testing and correlate these with the genetic mutations identified through linkage studies and eventually to the genes (genetic mutations) as they become identified.

Studietype

Observasjonsmessig

Registrering

200

Kontakter og plasseringer

Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.

Studiesteder

  • Forente stater
    • Maryland
      • Bethesda, Maryland, Forente stater, 20892
        • National Eye Institute (NEI)

Deltakelseskriterier

Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.

Kvalifikasjonskriterier

Alder som er kvalifisert for studier

  • Barn
  • Voksen
  • Eldre voksen

Tar imot friske frivillige

Nei

Kjønn som er kvalifisert for studier

Alle

Beskrivelse

Inclusion Criteria:

  • Patients must have documentation of neurosensory hearing loss and retinitis pigmentosa and fulfill the clinical characteristics (Table) as accepted for USH 1 and USH 2.
  • The minimal test battery will identify all patients with USH 1 and USH 2 as well as possible subtypes.
  • Candidates will be recruited from lists of patients willing to participate in research studies compiled by the R.P. Foundation, and by referral from their private physicians.
  • On occasion additional family members will be studied after an initial individual is ascertained as above.
  • No patients with intrauterine and childhood infections, and intrauterine and birth complications can result in trauma to both the auditory or visual system and a positive history for these conditions will necessitate exclusion from the study.

Studieplan

Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.

Hvordan er studiet utformet?

Samarbeidspartnere og etterforskere

Det er her du vil finne personer og organisasjoner som er involvert i denne studien.

Sponsor

National Eye Institute (NEI)

Publikasjoner og nyttige lenker

Den som er ansvarlig for å legge inn informasjon om studien leverer frivillig disse publikasjonene. Disse kan handle om alt relatert til studiet.

Generelle publikasjoner

Studierekorddatoer

Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.

Studer hoveddatoer

Studiestart

1. juni 1993

Studiet fullført

1. august 2002

Datoer for studieregistrering

Først innsendt

3. november 1999

Først innsendt som oppfylte QC-kriteriene

3. november 1999

Først lagt ut (Anslag)

4. november 1999

Oppdateringer av studieposter

Sist oppdatering lagt ut (Anslag)

4. mars 2008

Siste oppdatering sendt inn som oppfylte QC-kriteriene

3. mars 2008

Sist bekreftet

1. august 2002

Mer informasjon

Begreper knyttet til denne studien

Nøkkelord

Ytterligere relevante MeSH-vilkår

Andre studie-ID-numre

  • 930161
  • 93-EI-0161

Denne informasjonen ble hentet direkte fra nettstedet clinicaltrials.gov uten noen endringer. Hvis du har noen forespørsler om å endre, fjerne eller oppdatere studiedetaljene dine, vennligst kontakt register@clinicaltrials.gov. Så snart en endring er implementert på clinicaltrials.gov, vil denne også bli oppdatert automatisk på nettstedet vårt. .

Kliniske studier på Retinitis Pigmentosa

Søk i lignende forsøk

Sponsorer og samarbeidspartnere

Medisinsk tilstand

Legemiddelintervensjoner

CROs by country

CROs in Senegal

Forhold

Sjeldne sykdommer

Legemiddelintervensjoner

Kosttilskudd

Sponsor / samarbeidspartnere

Steder

3
Abonnere