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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®

Meesmann corneal dystrophy

Reviewed August 2012

What is Meesmann corneal dystrophy?

Meesmann corneal dystrophy is an eye disease that affects the cornea, which is the clear front covering of the eye. This condition is characterized by the formation of tiny round cysts in the outermost layer of the cornea, called the corneal epithelium. This part of the cornea acts as a barrier to help prevent foreign materials, such as dust and bacteria, from entering the eye.

In people with Meesmann corneal dystrophy, cysts can appear as early as the first year of life. They usually affect both eyes and increase in number over time. The cysts usually do not cause any symptoms until late adolescence or adulthood, when they start to break open (rupture) on the surface of the cornea and cause irritation. The resulting symptoms typically include increased sensitivity to light (photophobia), twitching of the eyelids (blepharospasm), increased tear production, the sensation of having a foreign object in the eye, and an inability to tolerate wearing contact lenses. Some affected individuals also have temporary episodes of blurred vision.

How common is Meesmann corneal dystrophy?

Meesmann corneal dystrophy is a rare disorder whose prevalence is unknown. It was first described in a large, multi-generational German family with more than 100 affected members. Since then, the condition has been reported in individuals and families worldwide.

What genes are related to Meesmann corneal dystrophy?

Meesmann corneal dystrophy can result from mutations in either the KRT12 gene or the KRT3 gene. These genes provide instructions for making proteins called keratin 12 and keratin 3, which are found in the corneal epithelium. The two proteins interact to form the structural framework of this layer of the cornea. Mutations in either the KRT12 or KRT3 gene weaken this framework, causing the corneal epithelium to become fragile and to develop the cysts that characterize the disorder. The cysts likely contain clumps of abnormal keratin proteins and other cellular debris. When the cysts rupture, they cause eye irritation and the other symptoms of Meesmann corneal dystrophy.

Related Gene(s)

Changes in these genes are associated with Meesmann corneal dystrophy.

  • KRT12
  • KRT3

How do people inherit Meesmann corneal dystrophy?

This condition is inherited in an autosomal dominant pattern, which means one copy of an altered KRT12 or KRT3 gene in each cell is sufficient to cause the disorder. In most cases, an affected person inherits the condition from an affected parent.

Where can I find information about diagnosis or management of Meesmann corneal dystrophy?

These resources address the diagnosis or management of Meesmann corneal dystrophy and may include treatment providers.

  • Genetic Testing Registry: Meesman's corneal dystrophy (
  • Merck Manual Home Health Handbook: Tests for Eye Disorders: The Eye Examination (

You might also find information on the diagnosis or management of Meesmann corneal dystrophy in Educational resources and Patient support.

General information about the diagnosis ( and management ( of genetic conditions is available in the Handbook. Read more about genetic testing (, particularly the difference between clinical tests and research tests (

To locate a healthcare provider, see How can I find a genetics professional in my area? ( in the Handbook.

Where can I find additional information about Meesmann corneal dystrophy?

You may find the following resources about Meesmann corneal dystrophy helpful. These materials are written for the general public.

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

What other names do people use for Meesmann corneal dystrophy?

  • corneal dystrophy, juvenile epithelial of Meesmann
  • corneal dystrophy, Meesmann epithelial
  • juvenile hereditary epithelial dystrophy
  • MECD
  • Meesmann corneal epithelial dystrophy
  • Meesmann epithelial corneal dystrophy
  • Meesman's corneal dystrophy

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines ( and How are genetic conditions and genes named? ( in the Handbook.

What if I still have specific questions about Meesmann corneal dystrophy?

Ask the Genetic and Rare Diseases Information Center (

What glossary definitions help with understanding Meesmann corneal dystrophy?

autosomal ; autosomal dominant ; bacteria ; cell ; cornea ; cysts ; epithelial ; epithelium ; gene ; hereditary ; inherited ; intermediate filaments ; juvenile ; keratin ; photophobia ; prevalence ; rupture ; sensitivity

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Corden LD, Swensson O, Swensson B, Smith FJ, Rochels R, Uitto J, McLEAN WH. Molecular genetics of Meesmann's corneal dystrophy: ancestral and novel mutations in keratin 12 (K12) and complete sequence of the human KRT12 gene. Exp Eye Res. 2000 Jan;70(1):41-9. (
  • Ehlers N, Hjortdal J, Nielsen K, Thiel HJ, Ørntoft T. Phenotypic variability in Meesmann's dystrophy: clinical review of the literature and presentation of a family genetically identical to the original family. Acta Ophthalmol. 2008 Feb;86(1):40-4. Epub 2007 Nov 6. Review. (
  • Irvine AD, Corden LD, Swensson O, Swensson B, Moore JE, Frazer DG, Smith FJ, Knowlton RG, Christophers E, Rochels R, Uitto J, McLean WH. Mutations in cornea-specific keratin K3 or K12 genes cause Meesmann's corneal dystrophy. Nat Genet. 1997 Jun;16(2):184-7. (
  • Klintworth GK. Corneal dystrophies. Orphanet J Rare Dis. 2009 Feb 23;4:7. doi: 10.1186/1750-1172-4-7. Review. (
  • Nishida K, Honma Y, Dota A, Kawasaki S, Adachi W, Nakamura T, Quantock AJ, Hosotani H, Yamamoto S, Okada M, Shimomura Y, Kinoshita S. Isolation and chromosomal localization of a cornea-specific human keratin 12 gene and detection of four mutations in Meesmann corneal epithelial dystrophy. Am J Hum Genet. 1997 Dec;61(6):1268-75. (
  • Smith F. The molecular genetics of keratin disorders. Am J Clin Dermatol. 2003;4(5):347-64. Review. (
  • Szaflik JP, Ołdak M, Maksym RB, Kamińska A, Pollak A, Udziela M, Płoski R, Szaflik J. Genetics of Meesmann corneal dystrophy: a novel mutation in the keratin 3 gene in an asymptomatic family suggests genotype-phenotype correlation. Mol Vis. 2008 Sep 15;14:1713-8. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: August 2012
Published: February 1, 2016