[Idiopathic juvenile osteoporosis].

Four cases (3 males and 1 female) of idiopathic juvenile osteoporosis, a rare form of bone demineralization, are described. The pathogenesis is unknown. The males showed osteoporosis at X-ray while in the female osteoporosis was only identified by computerized bone densitometry. The age of onset of the disease is perpuberal, but in one case it appeared in a small child. Biochemical data were in the normal range, only 1.25 (OH) 2D was reduced in two patients.