PDS5A and cleft palate: We detected several defects with incomplete penetrance and variable expressivity including cleft palate (20/61 in Pds5A−/−, 4/77 in Pds5A+/−, 0/39 in Pds5A+/+; Fig. 1C–F), presence of cervical ribs (10/10 in Pds5A−/−, 0/11 in Pds5A+/+; fusion of C7 and T1 or transformation of C7 to T1; Fig. 1G–J), abnormal sternum (5/10 in Pds5A−/−, 0/25 in Pds5A+/+; Fig. 1K–N) and abnormal patterns of vertebral ossification (17/26 in Pds5A−/−, 0/7 in Pds5A+/−, 0/3 in Pds5A+/+; Fig. 1O, P).