Pelizaeus-Merzbacher disease

What it is

Pelizaeus-Merzbacher disease (PMD) is an X-linked leukodystrophy characterized by developmental delay, nystagmus, hypotonia, spasticity, and variable intellectual deficit. It is classified into three sub-forms based on the age of onset and severity: connatal, transitional, and classic PMD.

Key facts

Prevalence

1-9 / 1 000 000 (Europe)

Age of onset

All ages

Inheritance

X-linked dominant, X-linked recessive

Classified as

Disease

Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.

Signs and symptoms

These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.

Genes reported in subtypes

Orphanet records this gene on 5 more specific entries under this disorder, not on this entry itself:

A well-studied disease is usually split into subtypes, and the gene is curated on whichever one the evidence belongs to. Open a subtype to see which gene goes with it.

ICD-10 codes

ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.

Related health topics

Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.

Cross-references