Juvenile Paget disease is a very rare form of Paget disease of the bone characterized by a general increase in bone turnover with increased bone resorption and deposition, resulting in cortical and trabecular thickening, and clinically presenting as progressive skeletal deformities, growth impairment, fractures, vertebral collapse, skull enlargement and sensorineural hearing loss. The disease is juvenile Paget disease (MONDO_0009394, a Monarch Disease Ontology term). Also known as: Hereditary Hyperphosphatasia, JPG, familial hyperphosphatasia, familial osteoectasia, hereditary hyperphosphatasia, hyperostosis corticalis deformans juvenilis, juvenile Paget's disease.