Of these disorders, the ones associated with heterozygous pathogenic variants in TUBB4A demonstrate a broad phenotypic spectrum, including primary dystonia (DYT4; Autosomal dominant torsion dystonia-4; MIM#128101), isolated hypomyelination, hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC; Hypomyelinating leukodystrophy 6; MIM#612438), as well as early infantile encephalopathy2. Here, TUBB4A is linked to hypomyelinating leukodystrophy 6.