BPNT1 and chondrodysplasia: To prevent their inhibition, rapid degradation of PAP in AMP and phosphate by a PAP phosphatase is important as demonstrated in chondrodysplasia with joint dislocations gPAPP type caused by mutations in the IMPAD1 gene (recently renamed BPNT2, 3′(2′), 5′-bisphosphate nucleotidase 2), encoding for a Golgi resident PAP phosphatase (gPAPP) or in the gene trap knock-out mice for the same gene [56,57,58].