Résumé : Campomelic dysplasia (CD) and its variant acampomelic campomelic dysplasia (ACD) are caused by SOX9 haploinsufficiency. This gene encodes a transcription factor crucial for embryogenesis and primarily expressed in the olfactory bulbs. The detection of agenesis of olfactory bulbs could help establish a prenatal diagnosis of CD or ACD, although prevalence of this sign remains unknown.