Pontocerebellar hypoplasia type 9

What it is

A rare, genetic, non-syndromic pontocerebellar hypoplasia characterized by progressive cerebellum and brainstem atrophy, corpus callosum hypo-/aplasia and progressive post-natal microcephaly. Patients typically present profound global developmental delay, spastic tetraparesis, seizures, cortical visual impairment and, on neuroimaging, abnormal brain morphology that includes pontocerebellar hypoplasia, ''figure of 8'' midbrain appearance, and, more variably, interhemispheric cysts, ventriculomegaly and cerebral dysmyelination.

Key facts

Prevalence

<1 / 1 000 000

Age of onset

Infancy, Neonatal

Inheritance

Autosomal recessive

Classified as

Clinical subtype

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.

Gene

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