[Osteopetrosis (report of 2 cases)].

Two distinct and characteristic cases of osteopetrosis are presented. The first concerns a fourth month old baby with the malignant form of the disease, initiated since the newborn period. He was admitted because of abnormal ocular movements and probably deafness. At the physical examination he showed bilateral optic atrophy, abnormal ocular movements, hepatosplenomegaly and petechia. The diagnosis was confirmed by clinical means and radiological studies of virtually all of his skeleton. Several fractures were found. Laboratory tests showed marked anemia, trombocytopenia "tear cells", evidence of medullary erythropoiesis and myelofibrosis. An increased alkaline phosphatase was detected in serum and in granulocytes. The second case corresponds to a 26 year-old female with the benign form of the disease. She had multiple pathological fractures specially of her lower limbs, that produced severe impotence in her gait. In this case, the diagnosis is suspected on clinical basis and confirmed with the characteristic radiological findings. Some of the more distinct features of the disease are discussed, specially those concerning the genetic mode of inheritance and consanguinity, the etiopathogenic, pathophysiology, clinical, laboratory, prognosis and treatment, with particular reference to the radiological and hematologic problems related with this metabolic disorder.