Spondyloepimetaphyseal Dysplasia, Aggrecan Type

Spondyloepimetaphyseal dysplasia, aggrecan type is a new form of skeletal dysplasia characterized by severe short stature, facial dysmorphism and characteristic radiographic findings.

Epidemiology

To date, three cases have been described, all originating from the same family.

Clinical description

Facial features include midface hypoplasia with almost absent nasal cartilage, and relative prognathism and macrocephaly. Radiographic findings include irregular epiphyses of long bones with widened metaphyses, platyspondyly, multiple cervical-vertebral clefts and brachydactyly.

Etiology

The disease results from a missense mutation affecting the C-type lectin domain of aggrecan (AGC1 gene; chromosome 15) which regulates endochondral ossification. Transmission is autosomal-recessive.