Dwarfism, pituitary: Dwarfism caused by a lack of growth hormone, usually due to malfunction of the pituitary gland. Children with growth hormone deficiency may grow normally for the first two to three years of life but they then fall behind their peers in height. They are normally proportioned. This is a key point. Treatment is with human growth hormone given in childhood. Also known as hypopituitary dwarfism, hypopituitarism, panhypopituitarism, and growth hormone deficiency.