Pelizaeus-Merzbacher is a neurological disorder involving myelin where there is a loss of the white matter in the brain which affects the central nervous system

Features of the disorder are flickering of the eyes (nystagmus), laboured breathing (stridor), spasticity and cognitive delay. The age of onset and progression of the disorder is very variable.

The disorder is usually caused by mutations in an important and abundant gene in myelin, proteolipid protein. In most cases the affected boys have an extra copy of the proteolipid protein (PLP) gene although the sequence of both copies is normal. In a minority of cases there is a mutation in the coding sequence of the PLP gene.

It is rare for a female with a mutation in the PLP gene to be affected and affected females with apparently similar clinical symptoms may have mutations in other, as yet unknown, genes.

Inheritance patterns
It is often inherited in an X-linked fashion, i.e. boys are affected and their female relatives, who are not themselves affected, may be carriers. The gene duplication can be detected by cytogenetic and molecular analysis in Regional Genetics Centres where counselling is also available.

Prenatal diagnosis
Prenatal diagnosis is available and has been carried out in a number of cases.

Medical text written April 2002 by Professor S Malcolm, Head of the Department of Molecular Genetics, Institute of Child Health, London, UK.

Further Online Resources
Medical texts in The Contact a Family Directory are designed to give a short, clear description of specific conditions and rare disorders. More extensive information on this condition can be found on a range of reliable, validated web sites and links to them are included in the CD-ROM version of this Directory. Further information on these resources can be found in our Medical Information on the Internet article.

PELIZAEUS-MERZBACHER SUPPORT GROUP

Pelizaeus-Merzbacher Support Group
c/o Contact a Family
209-211 City Road
London
EC1V 1JN
Tel: 0808 808 3555 Freephone Helpline
Tel: 0808 808 3556 Text
Tel: 020 7608 8700 Admin
Fax: 020 7608 8701
e-mail: pmdsupport@dsl.pipex.com

This is a small family support group offering support to families, newsletters and occasional events with a network of 50 families in touch.

Group details last updated August 2007.

As Pelizaeus-Merzbacher is a metabolic disease, support and advice are also available from Climb (see entry, Metabolic diseases).