Best Vitelliform Macular Dystrophy

Best Vitelliform Macular Dystrophy

National Organization for Rare Disorders, Inc.

Important

It is possible that the main title of the report Best Vitelliform Macular Dystrophy is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.

Synonyms

  • Best macular dystrophy
  • vitelliform macular dystrophy, type 2
  • vitelliform macular dystrophy, juvenile-onset
  • vitelliform macular dystrophy, early-onset
  • macular degeneration, polymorphic vitelline

Disorder Subdivisions

  • None

General Discussion

Best vitelliform macular dystrophy is an autosomal dominant genetic form of macular degeneration that usually begins in childhood or adolescence and slowly progresses to affect central vision. The age of onset and severity of vision loss are highly variable. Best vitelliform macular dystrophy is associated with an abnormality in the VMD2 gene.

Symptoms

Affected individuals initially have normal vision and then experience blurred vision, reduced sharpness or clarity of vision or the appearance objects that have a distorted shape (metamorphosia). Best vitelliform macular dystrophy affects central vision but usually not peripheral vision and varies in severity, even among members of the same family. Some people with the disorder do not notice a decline in vision, whereas others experience significant loss of vision, especially after 40 years of age. The degree of visual loss can be different in each eye.



The macula is the region of the retina that contains the light-sensing cells necessary for central vision. Individuals with Best vitelliform macular dystrophy develop a mass on the macula that resembles an egg yolk. (Vitelliform means yolk-like). This mass eventually breaks up and spreads throughout the macula, leading to a reduction in central vision.

Causes

Best vitelliform macular dystrophy is inherited as an autosomal dominant genetic condition. The VMD2 gene is the only gene that has been associated with this condition and has been mapped to chromosome 11q13. Some affected individuals do not have an abnormality in the VMD2 gene. Therefore, other genes may also be associated with this condition.



Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome and females have two X chromosomes. Each chromosome has a short arm designated "p" and a long arm designated "q". Chromosomes are further sub-divided into many bands that are numbered. For example, "chromosome 11q13" refers to band 13 on the long arm of chromosome 11. The numbered bands specify the location of the thousands of genes that are present on each chromosome.



Genetic diseases are determined by the combination of genes for a particular trait that are on the chromosomes received from the father and the mother.



Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. Most individuals affected with Best vitelliform macular dystrophy have an affected parent. The risk of passing the abnormal gene from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.

Affected Populations

Best vitelliform macular dystrophy is a rare disease and the prevalence is unknown. This condition has been diagnosed in individuals of European, African and Hispanic ancestry.

Standard Therapies

Diagnosis

Best vitelliform macular dystrophy is diagnosed by the appearance of a yellow mass on the macula during an eye exam, specialized testing of the eye called an electro-oculogram (EOG) and family history. Molecular genetic testing for the VMD2 gene is available to confirm the diagnosis.



Treatment

Affected individuals should have regular ophthalmologic examinations to monitor the progression of the disease. Low vision aids are beneficial for those who experience significant vision loss.



Genetic counseling is beneficial for affected individuals and their families.

Investigational Therapies

Direct laser photocoagulation may be useful in the treatment of Best vitelliform macular dystrophy, but clinical trials have not been conducted to evaluate this approach.



Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.



For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:



Tollfree: (800) 411-1222

TTY: (866) 411-1010

Email: prpl@cc.nih.gov



For information about clinical trials sponsored by private sources, contact:

www.centerwatch.com

References

JOURNAL ARTICLES

Blodi CF and Stone EM. Best's vitelliform dystrophy. Opthalmic Paediatr Genet 1990;11:49-59.



Eksandh L, Bakall B, Bauer B, et al. Best's vitelliform macular dystrophy caused by a new mutation (Val89Ala) in the VMD2 gene. Opthalmic Genet 2001; 22:107-15.



Fishman GA, Baca W, Alexander KR, et al. Visual acuity in patients with best vitelliform macular dystrophy. Opthalmology 1993;100:1165-70.



Loewenstein A, Godel V, Godel L, et al. Variable phenotypic expressivity of Best's vitelliform dystrophy. Opthalmic Paediatr Genet 1993;14:131-6.



Marano F, Deutman AF, Leys A, et al. Hereditary retinal dystrophies and choroidal neovascularization. Graefes Arch Clin Exp Opthalmol 2000;238:760-4.



Palmowski AM Allagayer R, Heinemann-Vernaleken B, et al. Detection of retinal dysfunction in vitelliform macular dystrophy using the multifocal ERG (MF-ERG). Doc Opthalmol 2003;106:145-52.



Petrukhin K, Koisti MJ, Bakall B, et al. Identification of the gene responsible for Best Macular dystrophy. Nat Genet 1998;19:241-7.



FROM THE INTERNET

MacDonald IM, Lee T, and Mah DY, (Updated 10/27/03). Best Vitelliform Macular Dystrophy. In: GeneReviews at GeneTests: Medical Genetics Information Resource (database online). Copyright, University of Washington, Seattle. 1997-2005. Available at http://www.genetests.org. Accessed 5/05.



Altaweel M. Best Disease. EMedicine. Last Updated: 10/4/04.



McKusick VA, ed. Online Mendelian Inheritance in Man (OMIM). Baltimore, MD: The Johns Hopkins University; Entry No. 153700; Last Update: 3/9/04.

Resources

Foundation Fighting Blindness

7168 Columbia Gateway Drive, Suite 100

Columbia, MD 21046

Tel: (410)423-0600

Fax: (410)872-0574

Tel: (800)683-5555

TDD: (800)683-5551

Email: info@FightBlindness.org

Internet: http://www.blindness.org/



Lighthouse International

111 E 59th St

New York, NY 10022-1202

Tel: (800)829-0500

Email: info@lighthouse.org

Internet: http://www.lighthouse.org



National Association for Parents of Children with Visual Impairments (NAPVI)

P.O. Box 317

Watertown, MA 02272-0317

Tel: (617)972-7441

Fax: (617)972-7444

Tel: (800)562-6265

Email: napvi@perkins.org

Internet: http://www.napvi.org



American Foundation for the Blind

2 Penn Plaza

Suite 1102

New York, NY 10121

Tel: (212)502-7600

Fax: (888)545-8331

Tel: (800)232-5463

TDD: (212)502-7662

Email: afbinfo@afb.net

Internet: http://www.afb.org



American Council of the Blind

2200 Wilson Boulevard

Suite 650

Arlington, VA 22201

Tel: (202)467-5081

Fax: (202)465-5085

Tel: (800)424-8666

Email: mailman@acb.org

Internet: http://www.acb.org/



Association for Macular Diseases, Inc.

210 E. 64th St.

8th Floor

New York, NY 10065

Tel: (212)605-3719

Fax: (212)605-3795

Email: association@retinal-research.org

Internet: http://www.macula.org/



NIH/National Eye Institute

31 Center Dr

MSC 2510

Bethesda, MD 20892-2510

United States

Tel: (301)496-5248

Fax: (301)402-1065

Email: 2020@nei.nih.gov

Internet: http://www.nei.nih.gov/



Genetic and Rare Diseases (GARD) Information Center

PO Box 8126

Gaithersburg, MD 20898-8126

Tel: (301)251-4925

Fax: (301)251-4911

Tel: (888)205-2311

TDD: (888)205-3223

Internet: http://rarediseases.info.nih.gov/GARD/



Retina International

Ausstellungsstrasse 36

CH-8005

Zürich,

Switzerland

Tel: 410444441077

Fax: 410444441070

Email: christina.fasser@retina-international.org

Internet: http://www.retina-international.org



For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc.® (NORD). Cigna members can access the complete report by logging into myCigna.com. For non-Cigna members, a copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use . How this information was developed to help you make better health decisions.

Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.