Skeletal dysplasia is a general term that covers multiple conditions affecting bone and cartilage. People with skeletal dysplasia are short in stature, with different sizes and shapes of legs, arms, trunk and skull.

This genetic condition, often referred to as "dwarfism," results from changes or defects (mutations) in one or more specific genes involved in growth. More than 350 different disorders of the skeleton fall under skeletal dysplasia, and have a wide range of clinical characteristics, ranging from quite mild to severe and even lethal.  Some types affect bone development and growth while others also affect mineralization (bone hardening). Approximately half of affected fetuses are either stillborn (23%) or expire during the first six weeks of life (32%).  Skeletal dysplasias are usually lethal due to the underdevelopment of the fetal ribs/chest, leading to underdeveloped fetal lungs (pulmonary hypoplasia).  The most severe (lethal) skeletal dysplasias are Thanatophoric dysplasia and achondrogenesis.  Achondroplasia is the most common non-lethal skeletal dysplasia.