Spondyloepiphyseal dysplasia Omani type: a new recessive type of SED with progressive spinal involvement.

We report a large inbred kindred from Oman with a distinct type of spondyloepiphyseal dysplasia (SED). We evaluated eight individuals from two consanguineous sibships, one male and seven females between the ages of 2 and 22. The pedigrees strongly suggest autosomal recessive inheritance and both families are likely to be related through distant consanguineous loops. The clinical features include near to normal length at birth, short stature with final height of 110-130 cm, shortening of the upper segment due to severe progressive kyphoscoliosis, severe arthritic changes with joint dislocations, rhizomelic limbs, genu valgum, cubitus valgus, mild brachydactyly, camptodactyly, microdontia, and normal intelligence. Minor radiographic metaphyseal changes were found, but major manifestations were in the spine and the epiphyses. During the first year of life the vertebral bodies are of normal height but the endplates are irregular and intervertebral space is narrow. With age, the vertebral endplates become increasingly irregular, the intervertebral space diminishes further and individual vertebrae start to fuse resulting in a severe short trunk dwarfism with kyphoscoliosis. The epiphysis are small and precocious osteoarthropathy was observed involving small and large joints. The elbow, wrist, and hip joints were affected starting in infancy and showed restricted movement. Osteoarthropathy and spinal involvement resulted in physical handicap in early adulthood. Comparison of these patients with other skeletal dysplasias suggests that they represent a previously undescribed variant of SED.