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Sponsored by: |
National Human Genome Research Institute (NHGRI) |
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Information provided by: | National Institutes of Health Clinical Center (CC) |
ClinicalTrials.gov Identifier: | NCT00808106 |
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 is considered isolated if it involves only tissues that are normally pigmented. The four known types of isolated oculocutaneous albinism (OCA-1 to OCA-4) are autosomal recessive disorders associated with specific genes. OCA-1 results from defects in the enzyme tyrosinase, which catalyzes the rate-limiting step in melanin synthesis. The precise functions of the genes associated with OCA2, OCA3 and OCA4 are not known. OCA-2 is caused by mutations in the OCA2 (or P) gene. OCA-3 and OCA-4 are rare, incompletely characterized conditions caused by the tyrosine-related protein 1 gene (TYRP1) and the SLC45A2 gene, respectively. Most OCA patients have two pathogenic mutations identified in an OCA-causing gene. In this protocol, we have 4 major goals. First, we want to clinically and comprehensively characterize OCA subtypes, especially OCA-1 and OCA-2, with respect to the degree of hypopigmentation, genetic mutations, and extent of ocular involvement. Second, we plan to study patients' cultured melanocytes for variability in pigment formation related to genotype, and test treatments to increase pigmentation. Third, we expect to ascertain rare patients with hypopigmentation not due to known albinism-causing genes. Finally, we will acquire sufficient experience in the care of patients with albinism to become experts in this disorder. This expertise will be especially valuable for potential future clinical trials. We will clinically evaluate patients of all ethnicities; obtain cells, plasma and urine for future studies; perform mutation analysis on known OCA causing genes; and search for other genes responsible for OCA. Routine admissions will last 4-5 days and occur every two years.
Condition |
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Albinism Oculocutaneous Albinism Foveal Hypoplasia Hypopigmentation Nystagmus |
Study Type: | Observational |
Official Title: | Clinical, Cellular, and Molecular Investigation Into Oculocutaneous Albinism |
Estimated Enrollment: | 300 |
Study Start Date: | December 2008 |
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 is considered isolated if it involves only tissues that are normally pigmented. The four known types of isolated oculocutaneous albinism (OCA-1 to OCA-4) are autosomal recessive disorders associated with specific genes. OCA-1 results from defects in the enzyme tyrosinase, which catalyzes the rate-limiting step in melanin synthesis. The precise functions of the genes associated with OCA2, OCA3 and OCA4 are not known. OCA-2 is caused by mutations in the OCA2 (or P) gene. OCA-3 and OCA-4 are rare, incompletely characterized conditions caused by the tyrosine-related protein 1 gene (TYRP1) and the SLC45A2 gene, respectively. Most OCA patients have two pathogenic mutations identified in an OCA-causing gene. In this protocol, we have 4 major goals. First, we want to clinically and comprehensively characterize OCA subtypes, especially OCA-1 and OCA-2, with respect to the degree of hypopigmentation, genetic mutations, and extent of ocular involvement. Second, we plan to study patients' cultured melanocytes for variability in pigment formation related to genotype, and test treatments to increase pigmentation. Third, we expect to ascertain rare patients with hypopigmentation not due to known albinism-causing genes. Finally, we will acquire sufficient experience in the care of patients with albinism to become experts in this disorder. This expertise will be especially valuable for potential future clinical trials. We will clinically evaluate patients of all ethnicities; obtain cells, plasma and urine for future studies; perform mutation analysis on known OCA causing genes; and search for other genes responsible for OCA. Routine admissions will last 4-5 days and occur every two years.
Ages Eligible for Study: | 1 Year to 80 Years |
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | No |
Patients will be considered to have a convincing diagnosis of OCA if they have cutaneous evidence of hypopigmentation plus:
A. Iris transillumination documented in writing or by photograph by an ophthalmologist; AND/OR
B. Evidence of characteristic axon-misrouting by visual evoked potential; AND/OR
C. Other visual deficits consistent with albinism, including nystagmus and/or foveal hypoplasia.
EXCLUSION CRITERIA:
A patient will be excluded if she/he:
A. Has been diagnosed with a known non-oculocutaneous disorder of hypopigmentation such as Hemansky-Pudlak Syndrome, Chediak-Higashi Syndrome, or Griscelli Syndrome.
B. Has been diagnosed with a known disorder of focal hypopigmentation such as Waardenburg syndrome.
C. Is too sick to travel to the NIH.
D. If an infant under one year of age. This exclusion occurs because there is no urgency for a very early evaluation. Also, the Clinical Center staff and resources are more suited for the care of older children.
Contact: Patient Recruitment and Public Liaison Office | (800) 411-1222 | prpl@mail.cc.nih.gov |
Contact: TTY | 1-866-411-1010 |
United States, Maryland | |
National Institutes of Health Clinical Center, 9000 Rockville Pike | Recruiting |
Bethesda, Maryland, United States, 20892 |
Study ID Numbers: | 090035, 09-HG-0035 |
Study First Received: | December 12, 2008 |
Last Updated: | January 27, 2009 |
ClinicalTrials.gov Identifier: | NCT00808106 History of Changes |
Health Authority: | United States: Federal Government |
Albinism Oculocutaneous Albinism Pigmentation Natural History Vesical Biology |
Hemostatic Disorders Albinism Metabolism, Inborn Errors Hypopigmentation Hemorrhagic Disorders Eye Diseases, Hereditary Hypomelanotic Disorder Skin Diseases, Genetic Metabolic Disorder Metabolic Diseases Skin Diseases Amino Acid Metabolism, Inborn Errors Hematologic Diseases |
Pigmentation Disorders Eye Diseases Blood Coagulation Disorders Blood Platelet Disorders Storage Pool Platelet Disease Platelet Storage Pool Deficiency Nystagmus, Pathologic Thrombocytopathy Genetic Diseases, Inborn Hermanski-Pudlak Syndrome Inborn Amino Acid Metabolism Disorder Albinism, Oculocutaneous Hermansky-Pudlak Syndrome |
Metabolic Diseases Skin Diseases Hematologic Diseases Amino Acid Metabolism, Inborn Errors Blood Platelet Disorders Blood Coagulation Disorders Eye Diseases Pigmentation Disorders Platelet Storage Pool Deficiency Albinism |
Hypopigmentation Metabolism, Inborn Errors Hemorrhagic Disorders Blood Coagulation Disorders, Inherited Genetic Diseases, Inborn Hermanski-Pudlak Syndrome Eye Diseases, Hereditary Albinism, Oculocutaneous Skin Diseases, Genetic |