The authors presented a case of the Williams and Beuren's syndrome, special by the existence of aorta coarctation, high blood pressure, nephrotic syndrome and renal dysplasia. The Williams-Beuren's syndrome is characterised by the association of facial anomalies, mental retardation and supra-valvular aortic stenosis. The case presented in this study demonstrates: -- the symptomatic diversity of the Williams and Beuren's syndrome; -- and the relationship of this syndrome and severe idiopathic hypercalcemia of the infant. The etiopathogenesis is also discussed.