Individuals with short stature or with a skeletal dysplasia known or suspected to be caused by a gene mutation (change) may be eligible for this study. Family members may also participate. Skeletal dysplasias under study include: achondroplasia, hypochondroplasia, achondrogenesis type II, hypochondrogenesis, Kniest dysplasia, spondyloepiphyseal dysplasias, Stickler syndrome; Shmid and Jansen metaphyseal dysplasias; pyknodysotosis, proximal symphalangism, brachydactyly types B C and E, Ellis van Creveld and related disorders, metatrophic chondrodysplasias, cartilage-hair hypoplasia and disorders with a skeletal abnormality that have not yet been defined but might be the result of a genetic defect.