Rare Ophthalmology News

Disease Profile

Meesmann corneal dystrophy

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 / 1 000 000

< 331

US Estimated

< 514

Europe Estimated

Age of onset

Childhood

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ICD-10

H18.5

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.

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)

Meesmann corneal epithelial dystrophy; Corneal dystrophy, juvenile epithelial of Meesmann; Juvenile hereditary epithelial dystrophy;

Categories

Congenital and Genetic Diseases; Eye diseases

Summary

Meesmann corneal dystrophy (MECD) is a rare genetic condition affecting the clear front covering of the eye (cornea). It is characterized by the development of multiple tiny round cysts in the outermost layer of the cornea (corneal epithelium). Over time, these cysts can break open (rupture) and cause irritation and erosions. Symptoms usually appear around adulthood and may include light sensitivity (photophobia), redness, and pain. Vision remains good in most individuals, but some individuals can have temporary episodes of blurred vision. MECD can be caused by mutations in the either the KRT3 gene or the KRT12 gene and is inherited in an autosomal dominant fashion.[1][2] While there is no cure for MECD, symptoms are usually effectively managed with use of lubricating eye drops.[3]

Symptoms

Individuals with Meesmann corneal dystrophy usually do not have symptoms until adulthood, when the cysts on the cornea break open (rupture) and cause irritation and recurrent erosions. Symptoms may include light sensitivity (photosensitivity), contact lens intolerance, redness, pain, twitching of the eyelids (blepharospasm), increased tear production, the sensation of having a foreign object in the eye, and occasionally blurred vision (irregular corneal astigmatism).[4][1]

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
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
0000006
Corneal dystrophy
0001131
Epiphora
Increased tears
Tearing
Watery eyes

[ more ]

0009926
Nonprogressive
0003680
Photophobia
Extreme sensitivity of the eyes to light
Light hypersensitivity

[ more ]

0000613
Punctate opacification of the cornea
0007856
Reduced visual acuity
Decreased clarity of vision
0007663

Cause

MECD is a genetic disease passed through families in an autosomal dominant manner. It is caused by mutations in either the KRT12 or KRT3 gene. These genes are thought to play an important role in maintaining normal corneal epithelial function.[1]

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

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
  • Orphanet lists international laboratories offering diagnostic testing for this condition.

    Treatment

    Treatment is usually not needed unless a person is experiencing symptoms. Most people only need lubricating eye drops. If symptoms are more severe, therapeutic contact lenses or cycloplegic eye drops may be used for severe sensitivity to light (photophobia). Hypertonic saline may be given if symptoms get worse when a person wakes up. Surgical procedures are sometimes tried when these treatments do not help, and may include epithelial debridement, or keratectomy. There is a high risk of recurrence with these procedures. Researchers are also evaluating a form of gene therapy called RNA interference (RNAi) which is also called therapeutic siRNA. This therapy may be able to silence the mutated gene that causes Meesman corneal dystrophy.[4][5][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

        • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
        • Genetics Home Reference (GHR) contains information on Meesmann corneal dystrophy. 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

          • 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 Meesmann corneal dystrophy. 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. Meesmann corneal dystrophy. Genetics Home Reference. 08/2012; https://ghr.nlm.nih.gov/condition/meesmann-corneal-dystrophy. Accessed 11/8/2016.
              2. Gordon K Klintworth. Corneal dystrophies. Orphanet Journal of Rare Diseases. 23 February 2009; 4:7:https://www.ojrd.com/content/4/1/7. Accessed 5/22/2015.
              3. Jalbert, I, Stapleton, F. Management of Symptomatic Meesmann Dystrophy. Optometry and Vision Science. October 2009; 86(10):E1202-E1206. https://www.ncbi.nlm.nih.gov/pubmed/19741557. Accessed 1/2/2014.
              4. Corneal Dystrophies. In: Traboulsi EI. Genetic Diseases of the Eye. New York, NY: Oxford University Press; 1998;
              5. Liao H, Irvine AD, Macewen CJ, Weed KH, Porter L, Corden LD, Gibson AB, Moore JE, Smith FJ, McLean WH, Moore CB. Development of Allele-Specific Therapeutic siRNA in Meesmann Epithelial Corneal Dystrophy. PLoS One. 2011; 6(12):e28582. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3236202/. Accessed 1/2/2014.

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