Bidirectional (anterograde and retrograde) motor-based intraflagellar transport 
(IFT) governs cargo transport and delivery processes that are essential for 
primary cilia growth and maintenance and for hedgehog signaling functions. The 
IFT dynein-2 motor complex that regulates ciliary retrograde protein transport 
contains a heavy chain dynein ATPase/motor subunit, DYNC2H1, along with other 
less well functionally defined subunits. Deficiency of IFT proteins, including 
DYNC2H1, underlies a spectrum of skeletal ciliopathies. Here, by using exome 
sequencing and a targeted next-generation sequencing panel, we identified a 
total of 11 mutations in WDR34 in 9 families with the clinical diagnosis of 
Jeune syndrome (asphyxiating thoracic dystrophy). WDR34 encodes a WD40 
repeat-containing protein orthologous to Chlamydomonas FAP133, a dynein 
intermediate chain associated with the retrograde intraflagellar transport 
motor. Three-dimensional protein modeling suggests that the identified mutations 
all affect residues critical for WDR34 protein-protein interactions. We find 
that WDR34 concentrates around the centrioles and basal bodies in mammalian 
cells, also showing axonemal staining. WDR34 coimmunoprecipitates with the 
dynein-1 light chain DYNLL1 in vitro, and mining of proteomics data suggests 
that WDR34 could represent a previously unrecognized link between the 
cytoplasmic dynein-1 and IFT dynein-2 motors. Together, these data show that 
WDR34 is critical for ciliary functions essential to normal development and 
survival, most probably as a previously unrecognized component of the mammalian 
dynein-IFT machinery.