North Carolina macular dystrophy

Title

Other Names:

NCMD; Macular dystrophy retinal 1 North Carolina type; MCDR1; NCMD; Macular dystrophy retinal 1 North Carolina type; MCDR1; Central areolar pigment epithelial dystrophy; CAPED; Retinal pigment epithelial dystrophy central; Foveal dystrophy progressive See More

Categories:

Congenital and Genetic Diseases; Eye diseases

Summary Summary

North Carolina macular dystrophy (NCMD) is an inherited eye disorder characterized by abnormalities of the macula, a portion of the eye located in the center of the retina. The macula allows one to see fine details and do tasks that require central vision, such as reading and driving. Signs and symptoms are due to an accumulation of yellow-white spots or lesions (drusen) in the macula and to the loss of cells that respond to light (photoreceptors). The main symptom is blurred central vision, but color vision is typically normal. Symptoms usually do not worsen over time. Ophthalmoscopic (imaging of the back part of the eye) findings are variable. Depending on the severity of symptoms and retina damage, eye findings are classified in grade l, ll, or lll.^[1]^[2]^[3] NCMD is caused by mutations in a region of chromosome 6 (MCDR1), involving a DNase I hypersensitivity site (DHS6S1), where the genetic code (DNA) is exposed and easily broken down by proteins, such as DNase I. Mutations within this region may also influence the function of the PRDM13 gene.^[1]^[4] Although there is no cure for NCMD; treatment is based on symptoms. Low vision aids may be useful for individuals with decreased visual acuity.^[4]

Last updated: 11/1/2016

Symptoms Symptoms

The signs and symptoms of NCMD vary from person to person and usually do not worsen over time. The main symptom is blurred central vision with normal color vision. Findings on eye exam also vary and can be classified into three different grades depending on severity:

Grade 1: Collection of drusen in the macula at the level of the retinal pigment epithelium (cell layer just outside the retina)
Grade 2: Clustering and joining of the drusen with or without changes within the retinal pigment epithelium (RPE) and formation of scar tissue
Grade 3: Thinning of the outer, white coat of the eye (staphyloma) or loss of macular tissue (coloboma) with damage and loss of tissue in the choroid (layer of blood vessels and connective tissue between the white of the eye and retina) and retina (chorioretinal atrophy)

New blood vessels may also develop in the choroid (choroidal neovascularization); though this finding is rare.^[1]^[2]^[3]

Last updated: 11/1/2016

The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.

Signs and Symptoms	Approximate number of patients (when available)
Abnormality of macular pigmentation	-
Autosomal dominant inheritance	-
Drusen	-
Generalized aminoaciduria	-
Macular dystrophy	-

Last updated: 9/1/2017

Cause Cause

NCMD is a genetic condition caused by mutations in a region (locus) of chromosome 6, called MCDR1, between 6q14 and 6q16.2. There are a number of mutations within this region that have been associated with NCMD. This locus contains an enzyme (protein) called the DNase 1 hypersensitivity site, where the genetic code (DNA) is exposed and easily broken down by enzymes, such as DNase I. While it is not yet known exactly how mutations within this locus lead to the signs and symptoms of NCMD, it is suspected that they may influence the function of the PRDM13 gene, a gene thought to be involved in macular development.^[1]^[4]

Last updated: 11/1/2016

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Research Research

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

The Centers for Mendelian Genomics program is working to discover the causes of rare genetic disorders. For more information about applying to the research study, please visit their website.

Organizations 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

Foundation Fighting Blindness
7168 Columbia Gateway Drive, Suite 100
Columbia, MD 21046
Toll-free: 800-683-5555
Telephone: 410-423-0600 (local)
TTY: 800-683-5551
E-mail: info@fightblindness.org
Website: http://www.blindness.org

Do you know of an organization? Send us your suggestions.

Living With Living With

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Genetics Resources

To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by GeneTests, the American College of Medical Genetics, and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from Genetics Home Reference.

Learn More 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.

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 North Carolina macular dystrophy. Click on the link to view a sample search on this topic.

News & Events News & Events

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References References

MACULAR DYSTROPHY, RETINAL, 1, NORTH CAROLINA TYPE; MCDR1. OMIM. 8/11/2016; http://www.omim.org/entry/136550.
Rahul N. Khurana, Xufang Sun, Eric Pearson, Zhenglin Yang, Jennifer Harmon, Morton F. Goldberg, Kang Zhang. A Reappraisal of the Clinical Spectrum of North Carolina Macular Dystrophy. Ophthalmology. October 2009; 116(10):1976-1983. https://www.ncbi.nlm.nih.gov/pubmed/19616854.
Macular Dystrophy, North Carolina. Hereditary Ocular Disease A Database of Hereditary Ocular Disease. http://disorders.eyes.arizona.edu/handouts/macular-dystrophy-north-carolina.
Kent W. Small, et al. North Carolina Macular Dystrophy Is Caused by Dysregulation of the Retinal Transcription Factor PRDM13. Ophthalmology. January 2016; 123(1):9-28. https://www.ncbi.nlm.nih.gov/pubmed/26507665.