Other Osteochondrodysplasias

Diastrophic dysplasia (DTD) is a condition that results in abnormal bone and cartilage development. Individuals with DTD exhibit short stature, joint contractures, dislocations of large joints, and clubfoot deformity and can have progressive spine deformities. Mutations in the solute carrier family 26 member 2 (SLC26A2) gene, also known as the diastrophic dysplasia transporter (DTDST) gene on chromosome 5 result in DTD. When DTD is suspected clinically, skeletal survey radiographs can be helpful for identifying other skeletal deformities associated with DTD. Evaluation by a geneticist and molecular genetic testing for the SLC26A2 can provide confirmation of a diastrophic dysplasia diagnosis. Orthopedic treatment is determined based on each individual’s clinical phenotype and function. Ellis–van Crevald (EvC) was first described as a syndrome of abnormal teeth, thin/scarce hair, short limbs, polydactyly, distal phalangeal hypoplasia, and cardiomegaly. Physician now recognize an expanded list of clinical features as being part of EvC (also known as chondroectodermal dysplasia). Mutations in the EVC and EVC2 gene cause Ellis–van Crevald syndrome. Proteins produced by the EVC and EVC2 genes are found at the base of osteoblast primary cilia. Children with Ellis–van Creveld syndrome (EvC) exhibit short limb, with the bones of the lower leg and forearms disproportionately affected. Hand abnormalities, including polydactyly, hypoplastic phalanges, carpal bone malformations, and dysplastic nails are common. The treatment of EvC is individualized based on each child’s clinical presentation. Surgical intervention is commonly needed for polydactyly.