Hyperferritinemia Cataract Syndrome

Hyperferritinemia Cataract Syndrome

National Organization for Rare Disorders, Inc.

Important

It is possible that the main title of the report Hyperferritinemia Cataract Syndrome 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

  • hereditary hyperferritinemia cataract syndrome
  • HHCS

Disorder Subdivisions

  • None

General Discussion

Hyperferritinemia-cataract syndrome is an extremely rare genetic disorder characterized by the early onset of cataracts associated with persistently elevated levels of ferritin in the blood plasma. Ferritin is a protein that binds to iron and is used as an indicator of the body's iron stores. Cataracts are the only known complication associated with this disorder. Hyperferritinemia-cataract syndrome is caused by mutations to ferritin light chain (FTL) gene. This mutation is inherited as an autosomal dominant trait.

Symptoms

The only known symptom of hyperferritinemia-cataract syndrome is the early onset of cataracts, usually between the second and fourth decades of life. However, onset of the disorder has been reported in children as young as five and adults more than 40. The overall prognosis of the disorder is very good. The severity of the hyperferritinemia-cataract syndrome can vary greatly from one person to another even among members of the same family. Some individuals with characteristic mutations of the FLT gene have not developed any symptoms (asymptomatic).



Cataracts are characterized by a clouding (opacity) of the lenses of the eye and can affect vision. The lens of an eye is the clear front portion of the eye through which light passes. The light is focused on the retina, the thin nerve-rich membrane lining the back of the eye. The retina converts light into nerve impulses and relays the information along the optic nerve to the brain. Cataracts can potentially affect both eyes and may cause several symptoms. Evidence suggests that cataracts in hyperferritinemia-cataract syndrome may become progressively worse.



Individuals with hyperferritinemia-cataract syndrome may experience glare symptoms that are worse when driving at night or in bright sunlight. Glare symptoms means that headlights, lamps, and other lights may appear too bright or have a halo form around them. Some affected individuals may be abnormally sensitive to light (photophobia) or experience blurred or hazy vision.

Causes

Hyperferritinemia-cataract syndrome is caused by mutations of the ferritin light chain (FTL) gene. In some cases, a mutation may occur randomly as the result of a spontaneous genetic change (sporadically). Hyperferritinemia-cataract syndrome is inherited as an autosomal dominant trait.



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. The risk of passing the abnormal gene from affected parent to offspring is 50 percent for each pregnancy regardless of the sex of the resulting child.



Investigators have determined that the FTL gene is located on the long arm (q) of chromosome 19 (19q13.3-q13.4). 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 19q13.3-q13.4" refers to bands 13.3-13.4 on the long arm of chromosome 19. The numbered bands specify the location of the thousands of genes that are present on each chromosome.



Mutations of the FTL gene in hyperferritinemia-cataract syndrome affect a region of the gene known as the iron regulatory element (IRE). A specialized protein called iron regulatory protein (IRP) normally binds to the IRE and suppresses the creation of ferritin. Mutations of the IRE prevent the binding of this protein and ultimately results in elevated levels of ferritin it the blood plasma. Ferritin is also commonly found in the lenses of the eyes. In individuals with hyperferritinemia-cataract syndrome, excess amounts of ferritin have been found in the lenses of the eyes and are believed to cause the development of cataracts.

Affected Populations

Hyperferritinemia-cataract syndrome is an extremely rare disorder that affects males and females in equal numbers. More than 100 families with the disorder have been described in the medical literature. The prevalence of hyperferritinemia-cataract syndrome has been estimated at 1 in 200,000 people in the general population. Because the disorder is so rare, it often goes unrecognized or undiagnosed, making it difficult to determine the disorder's true frequency in the general population. Hyperferritinemia-cataract syndrome was first described in the medical literature in 1995.

Standard Therapies

Diagnosis

A diagnosis of hyperferritinemia-cataract syndrome is made based upon identification of characteristic symptoms (e.g., cataracts), a detailed patient history, a thorough clinical evaluation and a variety of specialized tests such as blood tests, which can reveal elevated levels of ferritin in the blood plasma.



Treatment

There is no specific treatment for hyperferritinemia-cataract syndrome. Cataracts are the only known complication of the disorder. Individuals are treated with corrective glasses, contact lenses and, if vision is impaired to the point of interference with daily activities, then cataract surgery is performed. During cataract surgery, the cloudy lens inside the eye is replaced with a clear plastic lens. This surgery is technologically advanced and has a high success rate.



Therapy involving the regular removal of blood via a vein (known as a venesection or phlebotomy) is a common therapy for disorders associated with excess iron in the blood, but is not recommended as a therapy for hyperferritinemia-cataract syndrome.



Genetic counseling may be of benefit for affected individuals and their families.

Investigational Therapies

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 NIH Clinical Center 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

TEXTBOOKS

Rimoin D, Connor JM, Pyeritz RP, Korf BR. Eds. Emory and Rimoin's Principles and Practice of Medical Genetics. 4th ed. New York, NY: Churchill Livingstone; 2002:2657.



JOURNAL ARTICLES

Del Castillo Rueda A, Fernandez Ruano ML. Hereditary hyperferritinemia cataracts syndrome in a Spanish family caused by the A40G mutation (Paris) in the L-ferritin (FTL) gene associated with the mutation H63D in the HFE gene. Med Clin (Barc). 2007;129:414-417.



Burdon KP, Sharma S, Chen S, et al. A novel deletion in the FTL gene causes hereditary hyperferritinemia cataract syndrome (HHCS) by alteration of the transcription start site. Hum Mutat. 2007;28:742.



Christiansen G, Mohney BG. Hereditary hyperferritinemia syndrome. J AAPOS. 2007;11:294-296.



Ismail AR, Lachlan KL, Mumford AD, Temple IK, Hodgkins PR. Hereditary hyperferritinemia cataract syndrome: ocular, genetic, and biochemical findings. Eur J Ophthalmol. 2006;16:153-160.



Lachlan KL, Temple IK, Mumford AD. Clinical features and molecular analysis of seven British kindreds with hereditary hyperferritinemia cataract syndrome. Eur J Hum Genet. 2004;12:790-796.



Craig JE, Clark JB, McLeod JL, et al. Hereditary hyperferritinemia-cataract syndrome: prevalence, lens morphology, spectrum of mutations, and clinical presentations. Arch Ophthalmol. 2003;121:1753-1761.



Ponka P. Rare causes of hereditary iron overload. Semin Hematol. 2002;39:249-262.



INTERNET

Online Mendelian Inheritance in Man (OMIM). The Johns Hopkins University. Hyperferritinemia-Cataract Syndrome. Entry No: 600886. Last Edited April 30, 2010. Available at: http://www.ncbi.nlm.nih.gov/omim/. Accessed March 2, 2012.



Beaumont C. Hyperferritinemia, Hereditary, with Congenital Cataracts. Orphanet. http://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=1580&Disease_Disease_Search_diseaseGroup=Hyperferritinemia--Hereditary--with-Congenital-Cataracts&Disease_Disease_Search_diseaseType=Pat&Disease%28s%29/group%20of%20diseases=Hereditary-hyperferritinemia-with-congenital-cataracts&title=Hereditary-hyperferritinemia-with-congenital-cataracts&search=Disease_Search_Simple. Last Updated April 2006. Accessed March 2, 2012.

Resources

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/



Iron Disorders Institute

PO Box 675

Taylors, SC 29687

USA

Tel: (864)292-1175

Fax: (864)292-1878

Tel: (888)565-4766

Email: info@irondisorders.org

Internet: http://www.irondisorders.org



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/



For a Complete Report

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