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.Last update: September 2008
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.
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.
All of the reported cases were sporadic and the mode of inheritance remains unclear.