RESUMO
Rickets is a syndrome, characterized pathophysiologically by a failure of normal mineralization of bone and epiphyseal cartilage and clinically by skeletal deformity in growing children. The five principal causes of rickets are vitamin D deficiency, absorptive defects, renal tubular insufficiency, chronic renal insufficiency and hypophosphatasia. In addition to these causes of rickets a defective reabsorption mechanism of the proximal renal tubule is currently believed to be a factor in the development of hypophosphatemic vitamine D resistant rickets. Simple type of hypophosphatemic vitamine D resistant rickets is the most common of all the cases of rickets due to tubular insufficiency. It has a familiar incidence and is a sex-linked dominant disease. There is hypophos-phatemia and an elevated alkaline phosphatase but usually no glomerular disease or uremia. All the clinical manifestations are those of advanced rickets of the ordinary type and usually begin early. We experienced four cases of hypophosphatemic vitamine D resistant rickets which developed in a family.