Rapid progression of long-segment coarctation in a patient with Williams' syndrome.

Over a period of 6 days, a three-week-old male developed a long-segment coarctation, with sub-total obstruction of the descending aorta, immediately distal to the left subclavian artery. On the 24th day of life, the stenotic region was repaired by placement of a pulmonary allograft patch measuring 3 centimetres in length. Severe diffuse vascular medial thickening was discovered at the operation. Subsequent fluorescence in-situ hybridization proved positive for Williams' syndrome. To our knowledge, this is the first report of rapidly progressive infantile arteriopathy in the setting of Williams' syndrome.