Ectromelia is an inherited disorder where bones that are long are either underdeveloped or missing. There are four types of this disease and they include: Amelia is a birth defect with one or more limbs missing or they may be deformed or shrunken; Phocomelia is a form of ectromelia that is very rare; Hemimelia the genetic absence of the fibula; and Sirenomelia also known as “Mermaid Syndrome” is a rare genetic deformity where the legs are joined together forming the look of tail of a mermaid.