TUBB4A and Hypomyelination with atrophy of basal ganglia and cerebellum: 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.