[Syndrome of supravalvular aortic stenosis (Williams-Beuren syndrome) in association with changes in the kidney and efferent urinary tract].

We investigated the urinary tract in 19 out of 30 children having the Williams-Beuren-Syndrome. 14 of these children showed all signs of the syndrome, whereas 8 children had only the typical cardiological findings without the pathognomonic facies and without major mental retardation. These two different types will be designed as type I and type II respectively. In 12 of the children belonging to type I there were anomalies of the kidneys and the lower urinary tract including 1 child having nephrocalcinosis. The various anomalies were found as single or combined lesions. As for type II there was only 1 child (out of 5) that showed a stenosis of the urethra and at the origin of the ureter in combination with a hydronephrosis. The frequency of anomalies of the urinary tract appears to be very high in type I. However, because of the small number of patients it is impossible to reach statistical significance in comparing the different frequencies within type I and type II. Further investigations are necessary to clarify the problem.