We report on 6 patients with short stature and progressive enchondromatous-like changes of the vertebral bodies and the metaphyses of the long bones. Parental consanguinity was observed in 5 of 6 cases, supporting autosomal recessive inheritance. In spite of the similarity in radiographic changes and body proportions, genetic heterogeneity is suggested by the presence of CNS calcifications in 3 patients. Two of the latter had progressive quadriparesis. We tentatively classified these patients into 2 provisional types. An iliac crest biopsy in one of the patients with "type I" disease did not demonstrate enchondromatosis. Light and transmission electron microscopic studies demonstrated large cisterns and small inclusion bodies containing a flocculent material within the rough endoplasmic reticulum of the chondrocytes. Based on the histological and radiographic findings, we propose to classify these conditions among the spondylometaphyseal skeletal dysplasias.