Primary bone dysplasia with disorganized development of skeletal components
-Rare bone disease
-Rare developmental defect during embryogenesis
-Rare genetic disease
Le Merrer et al. (1991) described 4 patients from the same family with a characteristic localization of chondromatosis: clavicle, upper end of humerus, and lower end of femur (hence, 'geno-' for knee). The patients were a mother and ... Le Merrer et al. (1991) described 4 patients from the same family with a characteristic localization of chondromatosis: clavicle, upper end of humerus, and lower end of femur (hence, 'geno-' for knee). The patients were a mother and her daughter and 2 sons. The condition showed a benign course and was clearly different from metachondromatosis (156250), generalized enchondromatosis (166000), and spondyloenchondrodysplasia (271550). - Clinical Variability Kozlowski and Jarrett (1992) described a family with similar yet distinctive findings to those described by Le Merrer et al. (1991). They reported an autosomal dominant disorder with symmetric chondromata localized to the metaphyses of all the tubular long bones, but without involvement of the clavicles. The radius and ulna showed abnormal shape and there was coxa vara. The vertebral bodies were square-shaped. Kozlowski and Jarrett (1992) proposed the name genochondromatosis II for the disorder affecting their patients to distinguish it from the disorder described by Le Merrer et al. (1991). Isidor et al. (2007) reported a 12-year-old boy who had radiographic metaphyseal changes consistent with chondromas in the lower femoral and radial metaphyses as well as in the phalanges, metacarpals, and metatarsals. The changes formed irregular bands parallel to the longitudinal axis of the bone with lucencies and increased densities. The clavicles, skull, and spine were unaffected. Radiographic examination of the parents was normal, suggesting a de novo mutation. Isidor et al. (2007) stated that the skeletal findings in this patient were similar to those of the proband with 'genochondromatosis type II' described by Kozlowski and Jarrett (1992) and also to the 'expansile bone lesions' (603439) in the 3-generation family described by Dinulos et al. (1999); Isidor et al. (2007) suggested that the latter family might represent a variable form of the same disorder.