Spondyloepiphyseal dysplasia tarda
Spondyloepiphyseal dysplasia tarda is a chondroplasia that is due to a mutation in the SEDL gene (TRAPPC2). The corresponding protein, sedlin, plays a role in intracellular protein transport.
It is unclear why a mutation affects cartilage and bone growth in particular. The X-chromosomal variant is the most common form of this disease and appears exclusively in male patients. Affected individuals are characterized by disproportionate dwarfism, malformed limbs and trunk, and a barrel-shaped thorax. Joint pain mainly occurs in the large joints. Like the suffix "tarda" already indicates, the disease only manifests in the later stages of childhood or adolescence, but a pathological X-ray image can already be made on beforehand.
Some patients may reach a height of more than 1.50m, so there is often a lack of dwarfism.