Monarch Disease Ontology entry MONDO_0010961 (obesity due to prohormone convertase I deficiency) can be described as follows. Prohormone convertase-I deficiency is the rarest form of monogenic obesity. The disorder is characterized by severe childhood obesity, hypoadrenalism, reactive hypoglycaemia, and elevated circulating levels of certain prohormones. Also known as: PCI deficiency, PCSK1 Deficiency, obesity with impaired prohormone processing.