POLR3B and leukodystrophy: Patients with 4H leukodystrophy also presented delayed puberty or primary amenorrhea, including 27/33 patients with POLR3A (81%) and 20/29 patients (69%) with POLR3B mutations.[13] Furthermore, 20% patients had vertical gaze palsy, 19% patients with epilepsy, 87% with dental abnormalities, 72% with hypodontia, 87% with myopia, and 51% with short stature.[13] Moreover, almost all of these patients had hypomyelination in magnetic resonance imaging and POLR3B patients had cerebellar atrophy.