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Disease Profile

Macular telangiectasia type 2

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.

Unknown

Age of onset

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ICD-10

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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)

Idiopathic juxtafoveal retinal telangiectasis; Idiopathic juxtafoveal telangiectasis; IJT;

Categories

Eye diseases

Summary

Macular telangiectasia (MacTel) type 2 is an eye disease affecting the macula that causes loss of central vision. MacTel develops when there are problems with the tiny blood vessels (capillaries) around the fovea, an area in the center of the macula where eyesight is the sharpest. In MacTel type 2, the capillaries around the fovea widen (become dilated) and leak. This causes fluid build-up and swelling, impairing reflection of light and causing progressive vision loss. As damage continues, new blood vessels may form, which can break and leak. This can lead to the development of scar tissue, further impairing central vision. MacTel type 2 affects both eyes and occurs most often in middle-aged adults.[1][2][3]

Symptoms of MacTel type 2 can be subtle at first and may include slow loss of vision, distorted vision, blurring, trouble reading, and a spot of decreased or absent vision in the visual field.[1][2] The vision loss in MacTel type 2 generally progresses over ten to twenty years (sometimes more). However, there may be periods when symptoms do not worsen, interspersed with episodes of sudden worsening of vision.[2][3] MacTel type 2 usually does not cause total blindness, but vision loss can significantly impact quality of life.[1][3]

The underlying cause of MacTel type 2 is not known (idiopathic). While it sometimes "runs in families" and may have a genetic component, no specific genes responsible for MacTel type 2 have been identified.[3][4][5] Environmental factors may also play a role in the development of MacTel type 2.[5] Some researchers believe that people with diabetes, hypertension, obesity, or other health problems may be at increased risk for developing MacTel type 2.[1][4]

Vision loss associated with MacTel type 2 may be permanent. While no treatment has been proven to prevent progression, treatment may be helpful in some cases. Treatment options may include injection of anti-VEGF medications to limit the growth of new blood vessels, and the use of low vision aids.[1][2][6]

Cause

The underlying cause of macular telangiectasia (MacTel) type 2 is not yet known (idiopathic). MacTel type 2 sometimes "runs in families."[3][4] There have been published reports of siblings (including identical twins), as well as parents and children who have had MacTel type 2. While this suggests that genes play a role in causing at least some cases of MacTel type 2, no specific genes responsible for MacTel type 2 have been identified.[3][4][5] Environmental factors as well as interactions between genes and environment may also play a role inn the development of MacTel type 2.[5]

Some researchers have speculated that people with diabetes, hypertension, obesity, or other health problems may be at increased risk for developing MacTel type 2.[1][4] However, the possible associations between these health problems and MacTel type 2 need further study.

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

        In-Depth Information

        • 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.
        • 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 Macular telangiectasia type 2. Click on the link to view a sample search on this topic.

          Selected Full-Text Journal Articles

          • Charbel Issa P, Gillies MC, Chew EY, Bird AC, Heeren TF, Peto T, Holz FG, Scholl HP. Macular telangiectasia type 2. Prog Retin Eye Res. 2013 May;34:49-77.

            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. Boyd K, Vemulakonda GA. What Is Macular Telangiectasia?. American Academy of Ophthalmology. April 27, 2018; https://www.aao.org/eye-health/diseases/macular-telangiectasia.
              2. Macular Telangiectasia (“MacTel”). Macular Disease Foundation Australia. July, 2015; https://www.mdfoundation.com.au/sites/default/files/MDFA_MacularTelangiectasia-MacTel_Factsheet_web.pdf.
              3. About Macular Telangiectasia (MacTel). The Lowy Medical Research Institute. https://www.lmri.net/mactel/macular-telangiectasia-mactel/. Accessed 5/3/2018.
              4. Scerri TS, Quaglieri A, Cai C, et al. Genome-wide analyses identify common variants associated with macular telangiectasia type 2. Nat Genet. April, 2017; 49(4):559-567. https://www.nature.com/articles/ng.3799.
              5. Charbel Issa P, Gillies MC, Chew EY, et al. Macular telangiectasia type 2. Prog Retin Eye Res. May, 2013; 34:49-77. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3638089/.
              6. Idiopathic Juxtafoveal Telangiectasis. American Society of Retina Specialists. 2016; https://www.asrs.org/content/documents/fact_sheet_28_idiopathic_juxtafoveal_telangiectasis.pdf.
              7. Nowilaty SR, Al-Shamsi HN, Al-Khars W. Idiopathic juxtafoveolar retinal telangiectasis: a current review. Middle East Afr J Ophthalmol. July, 2010; 17(3):224-241. Accessed 2/10/2014.

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