Multicentric study of several ransgenic mouse models for human osteochondrodysplasias (achondroplasia, Ellis van-Creveld dysplasia, osteopoikilosis, diastrophic dysplasia, neurofibromatosis type I). The principle objective is to determine the molecular, cell and extracellular matrix pathology of a number of distinct skeletal dysplasia phenotypes by studying a series of mouse models using a multidisciplinary systems biology approach.