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Disease Profile

Ocular albinism type 1

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
1-9 / 1 000 000

331 - 2,979

US Estimated

1-9 / 1 000 000

514 - 4,622

Europe Estimated

Age of onset

Infancy

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ICD-10

E70.3

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

Nettleship-Falls type ocular albinism; OA1; X-linked recessive ocular albinism;

Categories

Congenital and Genetic Diseases; Eye diseases; Metabolic disorders

Summary

Ocular albinism type 1 (OA1) is a genetic eye condition that primarily affects males. Signs and symptoms may include reduced coloring of the iris and retina (ocular hypopigmentation); foveal hypoplasia (underdevelopment); rapid, involuntary eye movements (nystagmus); poor vision; poor depth perception; eyes that do not look in the same direction (strabismus); and increased sensitivity to light.[1][2] It is caused by mutations in the GPR143 gene and is inherited in an X-linked recessive manner.[1][2] Females have been affected in rare instances. Treatment consists of visual correction with eyeglasses or contact lenses; use of sunglasses or special filter glasses for light sensitivity; and in some cases, extraocular muscle surgery to restore alignment and/or improve head posture that is associated with nystagmus.[2]

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal pupil morphology
Abnormality of the pupil
Pupillary abnormalities
Pupillary abnormality

[ more ]

0000615
Astigmatism
Abnormal curving of the cornea or lens of the eye
0000483
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
Ocular albinism
Absent pigmentation in the eye
0001107
Photophobia
Extreme sensitivity of the eyes to light
Light hypersensitivity

[ more ]

0000613
30%-79% of people have these symptoms
Freckling
0001480
Hypoplasia of the fovea
0007750
Strabismus
Cross-eyed
Squint
Squint eyes

[ more ]

0000486
5%-29% of people have these symptoms
Giant melanosomes in melanocytes
0005592
Myopia
Close sighted
Near sighted
Near sightedness
Nearsightedness

[ more ]

0000545
Neoplasm of the skin
Skin tumors
Tumor of the skin

[ more ]

0008069
Visual impairment
Impaired vision
Loss of eyesight
Poor vision

[ more ]

0000505
Percent of people who have these symptoms is not available through HPO
Depigmented fundus
0007680
Nystagmus-induced head nodding
0001361
X-linked inheritance
0001417

Cause

Ocular albinism type 1 is caused by mutations in the GPR143 gene.[2] This gene gives the body instructions for making a protein that plays a role in pigmentation (coloring) of the eyes and skin. It helps control the growth of melanosomes, which are structures inside cells that make and store a pigment called melanin. Melanin also plays a role in vision in the retina. Mutations in the GPR143 gene can affect the protein's ability to do its job. As a result, melanosomes in skin and retinal cells can grow abnormally large, contributing to the signs and symptoms of the condition.[1] In rare cases, the genetic cause of this condition is unknown.

Diagnosis

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • Orphanet lists international laboratories offering diagnostic testing for this condition.

    Treatment

    Hypersensitivity to light, often called "photoaversion," "photophobia," or "photodysphoria," is the most incapacitating symptom in some people with ocular albinism type 1 (OA1). This symptom may be relieved by sunglasses, transition lenses, or special filter glasses, although many prefer not to wear them because of the reduction in vision from the dark lenses when indoors.

    Refractive errors should be detected and treated as early as possible with appropriate spectacle correction. Abnormal head posture may be treated with prismatic spectacle correction.

    Strabismus surgery is usually not necessary but may be performed for cosmetic purposes, particularly if the strabismus or the face turn is marked or fixed.

    Appropriate education for sun-protective lotions and clothing (preferably by an informed dermatologic consultant) is recommended to moderate the lifelong effects of sun exposure.

    Children with ocular albinism who are younger than 16 years of age should have an annual ophthalmologic exam (including assessment of refractive error and the need for filter glasses), as well as psychosocial and educational support. Affected adults should have ophthalmologic exams when needed, typically every two to three years.[3]

    Organizations

    Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

    Organizations Supporting this Disease

      Organizations Providing General Support

        Learn more

        These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

        Where to Start

        • Genetics Home Reference (GHR) contains information on Ocular albinism type 1. This website is maintained by the National Library of Medicine.
        • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

          In-Depth Information

          • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
          • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
          • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
          • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
          • PubMed is a searchable database of medical literature and lists journal articles that discuss Ocular albinism type 1. Click on the link to view a sample search on this topic.

            Diagrams/Images

            • A diagram of the eye can be found by visiting MedlinePlus, the National Library of Medicine Web site designed to help you research your health questions. Click on MedlinePlus to view the diagram.

              References

              1. Ocular albinism. Genetics Home Reference. 2007; https://ghr.nlm.nih.gov/condition=ocularalbinism. Accessed 7/24/2009.
              2. Gail Summers. X-linked recessive ocular albinism. Orphanet. April 2013; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=54. Accessed 6/27/2013.
              3. Richard Alan Lewis. Ocular Albinism, X-Linked. GeneReviews. April 5, 2011; https://www.ncbi.nlm.nih.gov/books/NBK1343/.
              4. Richard Alan Lewis. Ocular albinism, X-linked. GeneReviews. April 2011; https://www.ncbi.nlm.nih.gov/books/NBK1343/. Accessed 6/27/2013.
              5. Rosenberg T, Schwartz M. Ocular Albinism, X-Linked . GeneReviews. 2006; https://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=x-oa. Accessed 7/24/2009.

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