Two families with Dyggve-Melchior-Clausen syndrome are reported. In the first family, Jews from Morocco, six of 10 siblings are affected. In the second family, a consanguineous marriage of Arabs from Gaza, two of three children are affected. A description of the skeletal changes in patients ranging in age from 4 to 25 years is presented. The radiologic signs of generalized platyspondyly with double humped end plates and the lace-like appearance of thickened iliac crests are pathognomonic and distinctive of the syndrome. The diagnostic features of the disease are compared to those of Morguio's disease, spondyloepiphyseal dysplasia tarda, and spondylometaphyseal dysplasia.