Bietti's Crystalline Dystrophy Resource Guide

On this page:

• Other names
• What is Bietti's Crystalline Dystrophy?
• What causes Bietti's Crystalline Dystrophy?
• Can Bietti's Crystalline Dystrophy be treated?
• Research
• Resources
• Medical literature

The information provided in this Resource Guide was developed by the National Eye Institute (NEI) to help patients and their families in searching for general information about Bietti's crystalline dystrophy. An eye care professional who has examined the patient's eyes and is familiar with his or her medical history is the best person to answer specific questions.

Other names

Bietti's crystalline corneoretinal dystrophy

What is Bietti's Crystalline Dystrophy?

Bietti's crystalline dystrophy (BCD) is an inherited eye disease named for Dr. G. B. Bietti, an Italian ophthalmologist, who described three patients with similar symptoms in 1937. The symptoms of BCD include: crystals in the cornea (the clear covering of the eye); yellow, shiny deposits on the retina; and progressive atrophy of the retina, choriocapillaries and choroid (the back layers of the eye). This tends to lead to progressive night blindness and visual field constriction. BCD is a rare disease and appears to be more common in people with Asian ancestry.

People with BCD have crystals in some of their white blood cells (lymphocytes) that can be seen by using an electron microscope. Researchers have been unable to determine exactly what substance makes up these crystalline deposits. Their presence does not appear to harm the patient in any other way except to affect vision.

What causes Bietti's Crystalline Dystrophy?

From family studies, we know that BCD is inherited primarily in an autosomal recessive fashion. This means that an affected person receives one nonworking gene from each of his or her parents. A person who inherits a nonworking gene from only one parent will be a carrier, but will not develop the disease. A person with BCD syndrome will pass on one gene to each of his or her children. However, unless the person has children with another carrier of BCD genes, the individual's children are not at risk for developing the disease. More about autosomal recessive inheritance.

In September 2000, NEI researchers reported that the BCD gene had been localized to chromosome #4. In this region of chromosome #4 there are hundreds of genes. Researchers are now looking for which of the genes in this region of chromosome #4 causes BCD. Finding the gene may shed light on the composition of the crystals found in the corneas of patients with BCD and on what causes the condition. More about finding disease genes.

Can Bietti's Crystalline Dystrophy Be Treated?

At this time, there is no treatment for BCD. Scientists hope that findings from gene research will be helpful in finding treatments for patients with BCD.

Research

Researchers at the National Eye Institute's Ophthalmic Genetics and Visual Function Branch, see patients with BCD. Patients who are interested in being evaluated may contact:

Meira R. Meltzer, MA, MS
Genetic Counselor
National Eye Institute
(301) 402-4175
meira.meltzer@nih.gov

Resources

The following organizations may be able to provide additional information on Bietti's crystalline dystrophy:

National Organization for Rare Disorders, Inc. (NORD)
P.O. Box 8923
New Fairfield, CT 06812-8923
1-800-999-6673
(203) 746-6518
Fax: (203) 746-6481
http://www.rarediseases.org/

The Foundation Fighting Blindness
11435 Cronhill Dr
Owings Mills, MD 21117
1-800-683-5555
(410) 568-0150
Fax: (410) 363-2393
http://www.blindness.org

Medical Literature

Below is a sample of the citations available through MEDLINE/PubMed, a service of the National Library of Medicine. MEDLINE/PubMed provides access to over 11 million medical literature citations from 1966 to the present and includes links to many sites providing full text articles and other related resources. You can conduct your own free literature search by accessing MEDLINE through the Internet at http://medlineplus.nlm.nih.gov/hinfo.html. You can also get assistance with a literature search at a local library.

To obtain copies of any of the articles listed below, contact a local community, university, or medical library. If the library you visit does not have a copy of a particular article, you may usually obtain it through an inter-library loan.

Please keep in mind that articles in the medical literature are usually written in technical language. We encourage you to share any articles you order with a health care professional who can help you understand them.

Jiao X, Munier FL, Iwata F, Hayakawa M, Kanai A, Lee J, Schorderet DF, Chen MS, Kaiser-Kupfer M, Hejtmancik JF: Genetic linkage of Bietti crystalline corneoretinal dystrophy to chromosome 4q35. American Journal of Human Genetics 67:1309-1313, November 2000.
Bietti crystalline corneoretinal dystrophy (BCD) is an autosomal recessive retinal degeneration characterized by multiple glistening intraretinal dots scattered over the fundus, degeneration of the retina, and sclerosis of the choroidal vessels, ultimately resulting in progressive night blindness and constriction of the visual field. Although BCD has been associated with abnormalities in fatty-acid metabolism and absence of fatty-acid binding by two cytosolic proteins, the genetic basis of BCD is unknown. We report linkage of the BCD to chromosome 4q35.

Lee J, Jiao X, Hejtmancik JF, Kaiser-Kupfer M, Chader GJ: Identification, isolation, and characterization of a 32-kDa fatty acid-binding protein missing from lymphocytes in humans with Bietti crystalline dystrophy (BCD). Molecular Genetics and Metabolism 65(2):143-154, October 1998.
Bietti crystalline dystrophy (BCD) is an autosomal recessive retinal degeneration characterized by intraretinal lipid inclusions with degeneration of the retina and sclerosis of the choroidal vessels, resulting clinically in progressive night blindness and constriction of the visual fields. Characterization of fatty acid metabolism in Bietti crystalline dystrophy suggested that BCD might result from abnormalities in lipid-binding proteins or one or more enzymes active in fatty acid elongation and desaturation. To further investigate the first possibility, the docosahexaenoic acid-binding proteins (DHABPs) of human lymphocytes from patients with Bietti crystalline dystrophy were studied and compared with those of normal controls. Results suggest that the 32- and 43-kDa FABPs are reasonable candidates for causing BCD.

Kaiser-Kupfer MI, Chan C-C, Markello TC, Crawford MA, Caruso RC, Csaky KG, Guo J, and Gahl WA: Clinical, biochemical and pathologic correlations in Bietti's crystalline dystrophy. American Journal of Ophthalmology 118(5):569-582, November 1994.
We examined three affected members of a Chinese-American family with Bietti's crystalline retinopathy. The clinical characteristics of a 24-year-old proband are contrasted to the clinical findings of her grandmother, for whom we have 26 years of follow-up data. Lymphocytes and fibroblasts from a skin biopsy of the grandmother contained crystalline lysosomal material, which supports the diagnosis. Biochemical studies of the crystalline lysosomal material failed to identify the stored compounds but did not show them to be cholesterol or cholesterol ester. Finally, histopathologic studies performed for this condition demonstrated advanced panchorioretinal atrophy, with crystals and complex lipid inclusions seen in choroidal fibroblasts.

The National Eye Institute (NEI), part of the National Institutes of Health (NIH), is the Federal government's principal agency for conducting and supporting vision research. Inclusion of an item in this Information Resource Guide does not imply the endorsement by the NEI or the NIH.