Search for a rare disease
Other search option(s)
Pelizaeus-Merzbacher disease, classic form
Disease definition
The classic form of Pelizaeus-Merzbacher disease (PMD) is the infantile form of PMD.
ORPHA:280219
Classification level: Subtype of disorderSummary
Epidemiology
PMD has an estimated prevalence of 1/400,000. The classic form accounts for approximately 70% of all cases of PMD. It predominantly affects males.
Clinical description
The classic form of PMD manifests during the first months of life with nystagmus and hypotonia, which is progressively replaced by spasticity. Later signs include ataxia, sometimes associated with dystonia of the axis and limbs, weakness, dysarthria, impaired motor development and intellectual deficit. Patients may learn to walk with assistance and their speech is understandable but slow.
Etiology
The classic form of PMD is due most often to duplications but can also result from missense mutations of the PLP1 gene (on Xq22) that cause hypomyelination of the central nervous system. PLP1 encodes the proteolipid protein (PLP), the most abundant protein of the myelin sheath in the central nervous system, and its alternatively spliced isoform (DM20).
Genetic counseling
The disease has an X-linked inheritance pattern.
A summary on this disease is available in Deutsch (2011) Español (2011) Français (2011) Italiano (2011) Nederlands (2011) Português (2011) Polski (2011, pdf)
Detailed information
General public
- Article for general public
- English (2012) - Socialstyrelsen
- Svenska (2016) - Socialstyrelsen
Disease review articles
- Review article
- English (2011) - Expert Rev Neurother
- Clinical genetics review
- English (2019) - GeneReviews
produced/endorsed by ERN(s) 
produced/endorsed by FSMR(s)Additional information