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Clinical and Genetic Analysis of Enlarged Vestibular Aqueducts

This study is currently recruiting participants.
Verified October 2013 by National Institutes of Health Clinical Center (CC)
Sponsor:
Information provided by:
National Institutes of Health Clinical Center (CC)
ClinicalTrials.gov Identifier:
NCT00023036
First received: August 21, 2001
Last updated: March 14, 2014
Last verified: October 2013

August 21, 2001
March 14, 2014
August 2001
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Complete list of historical versions of study NCT00023036 on ClinicalTrials.gov Archive Site
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Clinical and Genetic Analysis of Enlarged Vestibular Aqueducts
Clinical and Molecular Analysis of Enlarged Vestibular Aqueducts

This study will try to identify and understand the genetic factors that lead to an inner ear malformation called "enlarged vestibular aqueducts", that can be associated with hearing loss.

Patients with sensorineural hearing loss with or without inner ear malformations and their parents and siblings may be eligible for this study. Participants and their immediate family members, may undergo some or all of the following tests and procedures:

  • Medical and family history, including questions about hearing, balance and other ear-related issues, and review of medical records.
  • Routine physical examination.
  • Blood draw or buccal swab (brushing inside the cheek to collect cells) - Tissue is collected for DNA analysis to look for changes in genes that may be related to hearing loss.
  • Hearing tests - The subject listens for tones emitted through a small earphone.
  • Balance test (VEMP) to see if balance functions of the inner ear are associated with the hearing loss Electrodes will be placed behind your ear and at the base of your neck. From a reclining position, you will be asked to raise your head while clicking sounds are played into your ears. - Ultrasound tests - An inner ear malformation called EVA (enlargement of the vestibular aqueduct) indicates that a genetic disorder called Pendred syndrome may be the cause. Because thyroid abnormalities are also associated with Pendred syndrome, an ultrasound examination of the thyroid gland may be done.
  • Computed tomography (CT) and magnetic resonance imaging (MRI) scans - These tests show the structure of the inner ear. For CT, the subject lies still for a short time while X-ray images are obtained. For MRI, the patient lies on a stretcher that is moved into a cylindrical machine with a strong magnetic field. The magnetic field and radio waves produce images of the inner ear. The radio waves cause loud thumping noises that can be muffled by the use of earplugs.

Nonsyndromic hereditary hearing impairment is a genetically heterogeneous disorder that can be caused by mutations in any one of at least 60 different genes. Enlargement of the vestibular aqueduct (EVA) is a radiologic finding known to be associated with mutations in one of these genes, the Pendred syndrome gene (SLC26A4, formerly known as PDS). EVA may thus serve as a clinically useful marker to facilitate the diagnosis of hearing impairment. Recent data from our laboratory and others indicates that only a subset of individuals with EVA have SLC26A4 mutations, and therefore some EVA cases are likely to be caused by other genes, nongenetic factors, or a combination of these etiologies. Families with two or more individuals with hearing impairment and EVA will be enrolled in this study in order to identify other genetic factors that cause EVA. Siblings and parents may also be enrolled in order to define inheritance and to perform molecular genetic analyses.

Observational
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  • Sensorineural Hearing Loss
  • Cytomegalovirus Infection
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*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruiting
500
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  • INCLUSION CRITERIA:

Subjects must have or be a family member of a participant with known or non-syndromic SNHL associated with inner ear malformations

There must be at least two participating affected family members.

Adults must be able to provide informed consent

Minors must have a parent or guardian able to provide consent

Age between 0-99.

EXCLUSION CRITERIA:

Subjects with known exposure to physical or chemical teratogens in utero that could account for their inner ear malformations such as thalidomide or radiation

Any hearing loss that is associated with syndromes, such as, branchio-oto-renal (BOR) syndrome, which comprises system malformations and branchial cleft abnormalities and is caused by heterozygous mutations in the EYA1 gene.

Previous genetic testing identifying two pathogenic mutant alleles of SLC26A4.

Both
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Contact: Julie Muskett (301) 435-1574 muskettj@mail.nih.gov
Contact: Andrew J Griffith, M.D. (301) 402-2829 griffita@mail.nih.gov
United States
 
NCT00023036
010228, 01-DC-0228
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National Institute on Deafness and Other Communication Disorders (NIDCD)
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Principal Investigator: Andrew J Griffith, M.D. National Institute on Deafness and Other Communication Disorders (NIDCD)
National Institutes of Health Clinical Center (CC)
October 2013

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP