Are the oral-facial-digital syndromes ciliopathies?

The first oral-facial-digital syndrome was described in 1941 by Mohr, followed by a report by Papillon-Léage and Psaume [Papillon-Léage and Psaume (1954); Rev Stomatol (Paris) 55:209-227]. Ironically, these became known as oral-facial-digital syndrome (OFDS) II and I, respectively. Since then, numerous other examples of OFDS have been published, and current classification systems include up to 13 different types of OFDS. Other than for OFDS I, the causative gene defects for these conditions are unknown. Recently however the finding that primary ciliary defects can cause multiple anomaly syndromes that phenotypically overlap with the OFDS suggests that many, if not all of the OFDS could be caused by mutations in ciliary proteins. This review presents the evidence for suggesting that the search for causative genes should focus on those that are related to ciliary structure and function.