First, Catel–Manzke syndrome shows clear phenotypic overlap with monogenic disorders of GAG metabolism, including the skeletal dysplasias Temtamy preaxial brachydactyly syndrome1,9 (OMIM: 605282), chondrodysplasia with joint dislocations, gPAPP type10–12 (linked to IMPAD1 (also known as BPNT2); OMIM: 614078) and Desbuquois dysplasia 1 and 213,14 (OMIM: 251450 and OMIM: 615777, respectively). The gene discussed is BPNT2; the disease is skeletal dysplasia.