Adrenoleukodystrophy

Adrenoleukodystrophy

National Organization for Rare Disorders, Inc.

Important

It is possible that the main title of the report Adrenoleukodystrophy 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

  • X- ALD
  • Addison Disease with Cerebral Sclerosis
  • Adrenomyeloneuropathy
  • ALD
  • AMN
  • Bronze Schilder Disease
  • Melanodermic Leukodystrophy
  • Schilder Disease
  • Siemerling-Creutzfeldt Disease
  • Sudanophilic Leukodystrophy

Disorder Subdivisions

  • None

General Discussion

Adrenoleukodystrophy is an X-linked recessive genetic disorder caused by an abnormality in the ABCD1 gene on the X chromosome. This condition affects the white matter of the nervous system and the adrenal cortex. Some affected individuals have adrenal insufficiency, which means that reduced amounts of certain hormones such as adrenaline and cortisol are produced, leading to abnormalities in blood pressure, heart rate, sexual development and reproduction. Some of those affected experience serious neurological problems that can affect mental function and lead to disability and reduced life span. This condition has been categorized into six types based on symptoms and age of onset: childhood cerebral ALD, adolescent cerebral ALD, adrenomyeloneuropathy, adult cerebral ALD, adrenal insufficiency only and ALD that occurs in females.

Symptoms

The childhood cerebral form of ALD usually begins between four and eight years of age and symptoms include attention deficit disorder, progressive loss of intellectual function, and vision, hearing and motor deterioration. Adolescent cerebral ALD begins between 11 and 21 years of age and the symptoms are similar to the childhood cerebral type but the disease progresses more slowly. The adrenomyeloneuropathy type of ALD usually begins in the late twenties and is characterized by difficulty walking, a progressive weakness and stiffness in the legs (paraparesis), a loss in ability to coordinate muscle movements, excessive muscle tone (hypertonia), vision loss, difficulty speaking dysarthria), seizures and adrenal insufficiency. Adult cerebral ALD can begin between the twenties and fifties with symptoms similar to schizophrenia with dementia. Individuals with adrenal insufficiency only do not initially have neurological problems, but symptoms such as those seen in adrenomyeloneuropathy usually develop later. ALD in females usually begins later in life and symptoms can vary greatly from mild to severe, but usually do not include adrenal insufficiency.

Causes

ALD is caused by an abnormality in the ABCD1 gene located on the X chromosome. This gene abnormality leads to the production of an abnormal ALDP protein in a part of the cell called the peroxisome, and is responsible for breaking down very long chain fatty acids. The accumulation of very long fatty acids damages the protective covering of nerves (myelin sheath), resulting in neurological problems.



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.



ALD is inherited as an X-linked recessive genetic disease. X-linked recessive genetic disorders are conditions caused by an abnormal gene on the X chromosome. Females have two X chromosomes but one of the X chromosomes is "turned off" and all of the genes on that chromosome are inactivated. Females who have a disease gene present on one of their X chromosomes are carriers for that disorder. Carrier females often do not display symptoms of the disorder because it is usually the X chromosome with the abnormal gene that is turned off. A male has one X chromosome and if he inherits an X chromosome that contains a disease gene, he will develop the disease. Males with X-linked disorders pass the disease gene to all of their daughters, who will be carriers. A male cannot pass an X-linked gene to his sons because males always pass their Y chromosome instead of their X chromosome to male offspring. Female carriers of an X-linked disorder have a 25% chance with each pregnancy to have a carrier daughter like themselves, a 25% chance to have a non-carrier daughter, a 25% chance to have a son affected with the disease, and a 25% chance to have an unaffected son.

Affected Populations

ALD is the most common leukodystrophy, accounting for about half of all leukodystrophies. The prevalence is approximately 1/20,000-1/50,000 births and most of those affected are boys. Approximately half of all females who carry the abnormal ABCD1 gene will develop some symptoms of ALD. The condition occurs in all ethnic groups.

Standard Therapies

Diagnosis

The concentration of very long fatty acids (VLFA) in blood plasma is elevated in 99% of males with ALD and in approximately 85% of female carriers of the abnormal ABCD1 gene. Molecular testing for the ABCD1 gene is available and is used primarily to confirm a diagnosis if other testing is not conclusive, to provide genetic counseling to family members and for prenatal diagnosis. Adrenal function tests are abnormal in 90% of boys with ALD who have neurologic symptoms and in approximately 70% of men with adrenomyeloneuropathy.



Treatment

The abnormal adrenal function is treated with corticosteroid replacement therapy. Bone marrow transplantation has been successful in individuals who are in the early stages of ALD.



Affected individuals can benefit from supportive care from psychologists, educators, physical therapists, urologists, and family and vocational counselors. Genetic counseling is recommended for affected individuals and their family members.

Investigational Therapies

Studies are underway to determine if Lorenzo oil therapy is beneficial in reducing the severity of neurological symptoms in individuals who do not yet have neurological problems. This therapy is not effective in altering the progression of the disease if the brain is already affected.



The Kennedy Krieger Institute and the General Clinical Research Center at Johns Hopkins Hospital are conducting (2006) a large NIH-funded study of Lorenzo's oil therapy in patients with adrenomyeloneuropathy (AMN). The study will involve 120 men and 120 women. Information about this study can be obtained by contacting Ms. Kim Hollandsworth (Hollandsworth@KennedyKrieger.org).



Studies are underway to determine if lovastatin and 4-phenylbutyrate are effective therapies for ALD.



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

Moser HW, Raymond GV, Lu SE, et al. Follow-up of 89 Lorenzo's oil treated asymptomatic adrenoleukodystrophy patients. Arch of Neurol 2005;62:1073-78.



Peters C, Charnas LR, Tan Y. Cerebral x-linked adrenoleukodystrophy: the international hematopoietic cell transplantation experience from 1982 to 1999. Blood 2004;104:881-88.



Aubourg P and Chaussain JL. Adrenoleukodystrophy:the most frequent cause of Addison's disease. Horm Res 2003;59(Suppl 1):104-5.



Bezman L, Moser AB, Raymond GV, et al. Adrenoleukodystrophy: incidence, new mutation rate and results of extended family screening. Ann Neurol 2001;49:512-7.



Shapiro E, Krivit W, Lockman L, et al. Long-term effect of bone-marrow transplantation for childhood-onset cerebral X-linked adrenoleukodystrophy. Lancet 2000;356:713-8.



Moser HW Smith KD, Watkins PA, et al. X-linked adrenoleukodystrophy. In: Scriver CR, Beaudet AL, Valle D, Sly WS, (eds) The Metabolic Basis of Inherited Disease, 8th ed. McGraw-Hill, New York:3257-302.



FROM THE INTERNET

McKusick VA, ed. Online Mendelian Inheritance in Man (OMIM). Baltimore, MD: The Johns Hopkins University; Entry No. 300100; Last Update:9/28/05.



Moser HW, Moser AB and Steinberg SJ. (Updated 4/15/04). X-Linked Adrenoleukodystrophy. In GeneReviews at Genetests: Medical Genetics Information Resource (database online). Copyright, University of Washington, Seattle. 1997-2005. Available at http://www.genetests.org. Accesssed 11/05.

Resources

CLIMB (Children Living with Inherited Metabolic Diseases)

Climb Building

176 Nantwich Road

Crewe, CW2 6BG

United Kingdom

Tel: 4408452412173

Fax: 4408452412174

Email: enquiries@climb.org.uk

Internet: http://www.CLIMB.org.uk



Kennedy Krieger Institute

707 North Broadway

Baltimore, MD 21205

Tel: (443)923-9200

Fax: (443)923-9405

Tel: (800)873-3377

TDD: (443)923-9400

Email: info@kennedykrieger.org

Internet: http://www.kennedykrieger.org



March of Dimes Birth Defects Foundation

1275 Mamaroneck Avenue

White Plains, NY 10605

Tel: (914)997-4488

Fax: (914)997-4763

Tel: (888)663-4637

Email: Askus@marchofdimes.com

Internet: http://www.marchofdimes.com



The Arc

1825 K Street NW, Suite 1200

Washington, DC 20006

Tel: (202)534-3700

Fax: (202)534-3731

Tel: (800)433-5255

TDD: (817)277-0553

Email: info@thearc.org

Internet: http://www.thearc.org



United Leukodystrophy Foundation

224 N. 2nd St.

Suite 2

DeKalb, IL 60115

Tel: (815)748-3211

Tel: (800)728-5483

Email: office@ulf.org

Internet: http://www.ulf.org/



ELA - European Association Against Leukodystrophies

2, rue Mi-les-Vignes

54521

Laxou Cedex, 61024

France

Tel: 33383309334

Fax: 33383300068

Email: ela@ela-asso.com

Internet: http://www.ela-asso.com



NIH/National Institute of Neurological Disorders and Stroke

P.O. Box 5801

Bethesda, MD 20824

Tel: (301)496-5751

Fax: (301)402-2186

Tel: (800)352-9424

TDD: (301)468-5981

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



ALD Family Support Trust

8 Morley House

320 Regent Street

London, W1B 3BB

United Kingdom

Tel: 02076313336

Fax: 02076313336

Internet: http://www.aldfst.org.uk



Hunter's Hope Foundation, Inc.

PO Box 643

6368 West Quaker Street

Orchard Park, NY 14127

Tel: (716)667-1200

Fax: (716)667-1212

Tel: (877)984-4673

Email: info@huntershope.org

Internet: http://www.huntershope.org



Australian Leukodystrophy Support Group, Inc.

Nerve Centre

54 Railway Road

Blackburn, VIC 3130

Australia

Tel: 61395847070

Tel: 1800141400

Email: mail@alds.org.au

Internet: http://www.alds.org.au



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/



Madisons Foundation

PO Box 241956

Los Angeles, CA 90024

Tel: (310)264-0826

Fax: (310)264-4766

Email: getinfo@madisonsfoundation.org

Internet: http://www.madisonsfoundation.org



Fight ALD

P.O. Box 3318

Vista, CA 92085

Tel: (760)212-5731

Email: info@fightald.org

Internet: http://www.fightald.org



Zellweger Baby Support Network

9310 Groundhog Drive

Richmond, VA 23235

Tel: (605)642-2072

Fax: (605)642-7525

Email: pamfreeth@zbsn.org

Internet: http://www.zbsn.org



ALD Life

PO Box 43642

London, SE22 0XR

United Kingdom

Tel: 02084737493

Email: info@aldlife.org

Internet: www.aldlife.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.

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