POLR3A and pneumonitis: Whereas, the mutations in the subunits POLR3A, POLR3C, POLR3E, and POLR3F are associated with susceptibility to varicella zoster virus-induced encephalitis and pneumonitis, the distinct mutations in the POLR3A, POLR3B, POLR1C, and POLR3K subunits cause a spectrum of neurodegenerative diseases, which includes the most notably hypomyelination leukodystrophy (Lata et al., 2021).