A leukodystrophy characterized by slowly progressive spasticity, extrapyramidal movement disorders (dystonia, choreoathetosis and rigidity), cerebellar ataxia, moderate to severe cognitive deficit, and anarthria/dysarthria. The disease is hypomyelinating leukodystrophy 6 (MONDO_0012905). Also known as: H-ABC, HABC, HLD6, hypomyelinating leukodystrophy type 6, hypomyelinating leukodystrophy with atrophy of the basal ganglia and cerebellum, hypomyelination with atrophy of basal ganglia and cerebellum, leukodystrophy, hypomyelinating, type 6.