A rare hypomyelinating leukodystrophy disorder in which the cause of the disease is a variation in any of the POLR genes, including POLR1C, POLR3A or POLR3B. It is characterized by the association of dental abnormalities (delayed dentition, abnormal order of dentition, hypodontia), hypogonadotropic hypogonadism, and hypomyelinating leukodystrophy manifesting with neurodevelopmental delay or regression and/or progressive cerebellar symptoms. The disease is Monarch Disease Ontology entry MONDO_0100605 (POLR-related leukodystrophy). Also known as: 4H leukodystrophy.