DDSH patients exhibit an absence of perlecan98 and varying degrees of myotonia and chondrodysplasia, whilst those with SJS deposit partially functional forms of perlecan, containing a defective domain V, into the cartilage ECM and exhibit multiple, early‐onset, skeletal abnormalities, including short stature and milder osteo‐chondrodysplasias.97 Here, HSPG2 is linked to chondrodysplasia.