Loss-of-function mutations in DYX1C1 and DCDC2 have been found in patients with ciliopathies: DYX1C1 in cases of primary ciliary dyskinesia, with ciliary defects also confirmed in mouse and zebrafish models [148], and DCDC2 in patients with nephronophthisis-related ciliopathy, inherited deafness and neonatal sclerosing cholangitis [150,151,152,153]. The gene discussed is DNAAF4; the disease is primary ciliary dyskinesia.