POLR3A and leukodystrophy, hypomyelinating, 7, with or without oligodontia and/or hypogonadotropic hypogonadism: Mutations in the POLR3A gene cause POLR3A-related hypomyelinating leukodystrophy with or without oligodontia or hypogonadotropic hypogonadism (HLD7, OMIM: 607694) and neonatal progeroid syndrome (OMIM: 264090), both with high phenotypic variability.