chronic, probably hereditary disorder characterized by kidney dysfunction, bone-mineral loss and rickets-type deformities, calcifications in abnormal places, and overactivity of the parathyroid glands. Loss of calcium and retention of phosphorus occur because of the malfunctioning kidneys; this induces an overproduction of parathormone, which results in the demineralization of well-formed bones (bone disease) and an inability to calcify newly developing bone. The bone abnormalities develop more slowly than kidney insufficiency; if the latter is severe, death may occur in childhood before the skeletal abnormalities become apparent. If the kidney insufficiency is not total, it may cause dwarfing and frequent fractures in children; adults experience gradual softening and bowing of bones. Secondary hyperparathyroidism, a type of renal osteodystrophy, may be an acquired disease found in individuals with chronic renal failure. Although the effect of acquired disease on bone metabolism is more limited than that of hereditary renal osteodystrophy, because of its onset late in life, it causes similar changes in calcium and phosphorus metabolism and bone demineralization over time.

Treatment of renal osteodystrophy depends on the state of chemical balance of the patient. Kidney transplant has been successful in some cases involving severe kidney dysfunction, and removal of the malfunctioning parathyroids is sometimes effective in controlling symptoms.