spondyloepimetaphyseal dysplasia—aggrecan type
Definition Spondyloepimetaphyseal dysplasia—aggrecan type is an autosomal recessive bone disorder (OMIM:612813) characterised by severe short stature, macrocephaly, midface hypoplasia, short neck, barrel chest and brachydactyly.
Imaging Long bones with irregular epiphyses and widened metaphyses, especially of the knees, platyspondyly, and multiple cervical-vertebral clefts.
Molecular pathology Defects of ACAN, which encodes aggrecan, a proteoglycan that is an integral part of the extracellular matrix in cartilage where it provides compressive resistance, cause spondyloepimetaphyseal dysplasia—aggrecan type.
Synonym SEMD—aggrecan type