Birth Prevalence and Mutation Rate of Achondroplasia in the Italian Multicentre Monitoring System for Birth Defects

Achondroplasia (Acp) is one of the most common forms of osteochondrodysplasia (OCD). The clinical and radiological features of this condition are at present well known, while the frequency and mutation rate have been until now rarely studied. The old estimate reported by Morch (1) is somewhat overestimated as for the diagnostic criteria used (2) since some non-achondroplastic conditions are included (3). More recent estimates of the Acp birth prevalence have been reported by Gardner (4) Oberklaid et al. (5) and Orioli et al. (6).