Skeletal dysplasia is a term used to describe over 200 different diseases that result in abnormalities in the development of bone or cartilage. Skeletal dyplasia can range from a condition commonly called dwarfism (achondroplasia) that results in a short body and limbs, to a condition called thanatophoric dysplasia where the child cannot live long after birth because the small rib cage does not allow the lungs to develop.
Each type of skeletal dysplasia is quite rare. When all skeletal dypslasias are taken together, they occur in approximately 2.4 per 10,000 births.
Because of the broad range of conditions that are included in the term skeletal dysplasia, it is important to try to differentiate between the different types before birth, if possible. When skeletal dysplasia is suspected on ultrasound, and the type of dysplasia is not clear from the ultrasound, one step in the management is genetic testing (usually by amniocentesis) to check a skeletal dysplasia panel, which is a combination of several genetic tests to determine which type of skeletal dysplasia is present. The prognosis and the care after birth depend on the type of skeletal dyplasia present. Children with achondroplasia (the most common skeletal dyplasia) may need orthopedic surgeries throughout their lives because of the shape of their bones, whereas children with the severe forms of skeletal dyplasia cannot live for a long time after birth.