Clinical, Cellular, and Molecular Investigation Into Oculocutaneous Albinism
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|ClinicalTrials.gov Identifier: NCT00808106|
Recruitment Status : Completed
First Posted : December 15, 2008
Last Update Posted : January 6, 2020
Oculocutaneous albinism (OCA) is a term used to describe inherited forms of hypopigmentation associated with 1) variable levels of cutaneous hypopigmentation, ocular hypopigmentation, and visual deficits, and 2) involvement of both of the major developmental types of pigmented cells, i.e., melanocytes and retinal pigment epithelium. OCA that affects only usually-pigmented tissues is termed isolated OCA. There are currently seven albinism types (OCA-1 to OCA-7). With the exception of OCA-5, eash is associated with a specific gene and is inherited in an autosomal recessive manner OCA-5 is a proposed type of albinism associated with the chromosomal location 4q24. OCA-1 results from defects in the enzyme tyrosinase, which catalyzes the rate-limiting step in melanin synthesis. The precise functions of the remaining genes are not yet fully understood, but several may be associated with the regulation of pH in the subcellular organelle where melanin in manufactured-the melanosome. The majority of persons with OCA have two pathogenic mutations identified in a known OCA-causing gene, but a substantial minority to not. Ocular albinism (OA) is an X-linked disorder caused by mutations in the GPR143 gene. It affects the eye in a manner similar to OCA, but has minimal or no skin manifestations.
In this protocol, we have four major goals:
- To clinically and comprehensively characterize OCA types 1 - 7, and OA, with respect to the degree of hypopigmentation, genetic mutations, extent of ocular involvement, and longitudinal variation.
- To use study participants cultured melanocytes to study pigment biology, variability in pigment formation related to genotype, and response to proposed treatments. Some of this work will be performed collaboratively.
- To recruit study participants with hypopigmentation not due to known albinismcausing genes.
- To evaluate methods of quantifying eye pigmentation, skin pigmentation and other clinical parameters that may be usable as outcome measures in future treatment studies.
To achieve those goals, we will perform clinical evaluations of persons with OCA and OA at the NIH Clinical Center; obtain cultured cells, plasma, serum and urine for future studies; and, perform mutation analysis on known OCA and/or OA genes and search for other genes responsible for albinism. Routine admissions will last 3 - 4 days and occur every 2 - 3 years.
|Condition or disease|
|Study Type :||Observational|
|Actual Enrollment :||206 participants|
|Official Title:||Clinical, Cellular, and Molecular Investigations Into Oculocutaneous Albinism|
|Actual Study Start Date :||December 11, 2008|
|Actual Primary Completion Date :||December 31, 2019|
|Actual Study Completion Date :||December 31, 2019|
Patients with albinism
- A [ Time Frame: Ongiong ]Collect data to refine existing knowledge about the range, course and severity of the visual, cutaneous, auditory and other potentialmanifestations of the various forms of OCA and of OA
- B [ Time Frame: Ongoing ]Conduct laboratory studies on patients cultured melanocytes and other biologic specimens to further understand the cell biology ofpigment formation relative to genetic mutation
- C [ Time Frame: Ongoing ]Pursue the discovery of novel molecular defects in patients who have albinism caused by mutations in pigmentation-related genes that have not yet been proven to be associated with human pigmentation disorders
- D [ Time Frame: Ongoing ]Search for and evaluate methods of quantifying eye pigmentation, skin pigmentation and other clinical parameters that may be usable as outcome measures in future treatment studies
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00808106
|United States, Maryland|
|National Institutes of Health Clinical Center, 9000 Rockville Pike|
|Bethesda, Maryland, United States, 20892|
|Principal Investigator:||David R Adams, M.D.||National Human Genome Research Institute (NHGRI)|