What is Pelizaeus-Merzbacher Disease?
Pelizaeus-Merzbacher disease (PMD) is a rare, progressive, degenerative central nervous system disorder in which coordination, motor abilities, and intellectual function deteriorate. The disease is one of a group of gene-linked disorders known as the leukodystrophies, which affect growth of the myelin sheath – the fatty covering that wraps around and protects nerve fibers in the brain. The disease is caused by a mutation in the gene that controls the production of a myelin protein called proteolipid protein-1 (PLP1). PMD is inherited as an X-linked recessive trait; the affected individuals are male and the mothers are carriers of the PLP1 mutation. Severity and onset of the disease ranges widely, depending on the type of PLP1 mutation. PMD is one of a spectrum of diseases associated with PLP1, which also includes Spastic Paraplegia Type 2 (SPG2). The PLP1-related disorders span a continuum of neurologic symptoms that range from severe central nervous system involvement (PMD) to progressive weakness and stiffness of the legs (SPG2).
There are four general classifications within this spectrum of diseases. In order of severity, they are:
- Connatal PMD, which is the most severe type and involves delayed mental and physical development and severe neurological symptoms;
- Classic PMD, in which the early symptoms include muscle weakness, involuntary movements of the eyes (nystagmus), and delays in motor development within the first year of life;
- Complicated SPG2, which features motor development issues and brain involvement, and,
- Pure SPG2, which includes cases of PMD that do not have neurologic complications.
Noticeable changes in the extent of myelination can be detected by MRI analyses of the brain. Additional symptoms of PMD may include slow growth, tremor, failure to develop normal control of head movement, and deteriorating speech and mental function.
Is there any treatment?
There is no cure for Pelizaeus-Merzbacher disease, nor is there a standard course of treatment. Treatment is symptomatic and supportive and may include medication for movement disorders.
What is the prognosis?
The prognosis for those with the severe forms of Pelizaeus-Merzbacher disease is poor, with progressive deterioration until death. On the other end of the disease spectrum, individuals with the mild form, in which spastic paraplegia is the chief symptom, may have nearly normal activity and life span.
What research is being done?
NINDS supports research on gene-linked disorders, including the leukodystrophies. The goals of this research are to increase scientific understanding of these disorders and to find ways to prevent, treat, and ultimately cure them.
United Leukodystrophy Foundation
224 North 2nd Street, Suite 2
DeKalb, IL 60115
Tel: 815.895.3211 800.728.5483
Hunter's Hope Foundation (A Leukodystrophy Resource)
P.O. Box 643
Orchard Park, NY 14127
Tel: 716.667.1200 877.984.HOPE (4673)
National Organization for Rare Disorders (NORD)
55 Kenosia Avenue
Danbury, CT 06810
Tel: 203.744.0100 Voice Mail 800.999.NORD (6673)
P.O. Box 39
Pacific Palisades, CA 90272
Tel: 800-869-3546 310-459-1071
PMD Foundation(Pelizaeus-Merzbacher Disease)
1 Greentree Center
1000 Lincoln Drive East, suite 201
Marlton, NJ 08053
Source:National Institutes of Health; National Institute of Neurological Disorders and Stroke
Can't find the health information you’re looking for?
This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 10/22/2012...#6107