Axial Spondylometaphyseal Dysplasia is an extremely rare autosomal recessive skeletal dysplasia characterized by short stature, progressive vision loss, thoracic hypoplasia, and spondylometaphyseal dysplasia. The bones of the chest, pelvis, spine, upper arms and upper legs are the ones that are primarily affected. The overall effect is one of shortened stature. Ocular anomalies seen in this condition include optic atrophy and/or retinitis pigmentosa. These features may manifest themselves in infancy or early childhood, and progress rapidly with age. Spine changes may also be seen, including scoliosis and flattened vertebrae. Thoracic hypoplasia may lead to breathing and recurring lung infections in some cases.
Axial SMD has been noted to follow an autosomal recessive pattern of inheritance. This is reinforced by the presence of consanguinity in the affected families. The causative gene is CFAP410 (C21orf2). This gene was suggested to have a role in ciliogenesis, especially pertaining to skeletal development and retinal function. It has also been speculated to play a role in the regulation of cell morphology and cytoskeletal organization.