Ignite Creation Date:
2024-05-05 @ 11:22 AM
Last Modification Date:
2024-10-26 @ 9:02 AM
Study NCT ID:
NCT00001347
Status:
COMPLETED
Last Update Posted:
2008-03-04
First Post:
1999-11-03
Brief Title:
Study of Usher Syndromes Type 1 and Type 2
Sponsor:
National Eye Institute NEI
Organization:
National Institutes of Health Clinical Center CC
Study Overview
Official Title:
Usher Syndrome - Clinical and Molecular Studies
Status:
COMPLETED
Status Verified Date:
2002-08
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
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
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
Detailed Description:
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
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
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| 93-EI-0161 | None | None | None |