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Hypomyelination with atrophy of basal ganglia and cerebellum

Synonym(s) H-ABC
Prevalence <1 / 1 000 000
Inheritance Autosomal dominant
Age of onset Infancy
  • E75.2
MeSH -
MedDRA -


Disease definition

Hypomyelination with atrophy of basal ganglia and cerebellum (H-ABC) is characterized by slowly progressive spasticity, extrapyramidal movement disorders (dystonia, choreoathetosis and rigidity), cerebellar ataxia, moderate to severe cognitive deficit, and anarthria/dysarthria.


So far, around 20 cases have been reported in the literature. The syndrome affects both males and females and onset occurs in infancy or early childhood.


The etiology is unknown.

Diagnostic methods

H-ABC is diagnosed on the basis of the distinctive MRI findings of diffuse but partial hypomyelination of the cerebral hemispheres, mild to severe cerebellar atrophy and atrophy of the basal ganglia.

Genetic counseling

All of the reported cases were sporadic and the mode of inheritance remains unclear.

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Detailed information

Review article
Clinical genetics review
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