Interestingly, both biglycan and aggrecan, two proteoglycans altered in MSS, have been associated with spondyloepimetaphyseal dysplasia, spondyloepiphyseal dysplasia, and chondrodysplastic dwarfism [55, 56]. Here, ACAN is linked to spondyloepimetaphyseal dysplasia, matrilin-3 type.