Differential diagnosis and other problems to be considered

Although more than 100 skeletal dysplasias that cause short stature are recognized, many are extremely rare, and all have clinical and radiographic features that readily distinguish them from achondroplasia. Results on antenatal ultrasonograms either suggest or confirm most skeletal dysplasias.

Conditions that may be confused with achondroplasia include achondrogenesis; chondroectodermal dysplasia; asphyxiating thoracic dystrophy; osteogenesis imperfecta; congenital hypophosphatasia; metatrophic dysplasia; Roberts syndrome; diastrophic dysplasia; short rib-polydactyly syndrome types I, II, and III; spondyloepiphyseal dysplasia congenita (camptomelic dysplasia); thanatophoric dysplasia; fibrochondrogenesis; chondrodysplasia punctate (rhizomelic type); Kniest dysplasia; mesomelic and acromesomelic dysplasia; hypochondroplasia; pseudoachondroplasia; and double heterozygosity in bone growth disorders.