Spondyloepiphyseal dysplasia, Reardon type

Definition

A rare spondyloepiphyseal dysplasia and spondyloepimetaphyseal dysplasia characterized by short stature, vertebral abnormalities (including irregular vertebral endplates especially in the dorsal spine, lumbar lordosis, spondylolysis, spondylolisthesis), femoral abnormalities (including small femoral capital epiphyses, flat femoral head and subluxation and sloping acetabulum) and cervical spine abnormalities typically manifest as atlantoaxial subluxation and instability associated with os odontoideum. Affected individuals present with severe neurological complications following minor trauma due to cervical instability, including quadriparesis, brisk reflexes, clonus, spasticity, bulbar palsy and seizures. Additional clinical features may include mild joint laxity, short, clubbed fingers, wasting of small hand muscles, tongue fasciculations and progressive breathing difficulty. There have been no further descriptions in the literature since 1994.