Aase Syndrome is a rare genetic disorder characterized by hypoplastic anemia, and joint and skeletal deformities. The most prominent joint deformity is the presence of three bones within the thumb, known as a triphalangeal thumb. In Aase Syndrome, the anemia is due to poor development of bone marrow [the center for production of red blood cells]. Other symptoms associated with this disorder include the absence of/or small knuckle bones, contracture deformities associated with the joints, decreased skin creases at finger joints, and a cleft palate. The exact causes of Aase Syndrome are unknown, but recent evidence suggests that the condition can be inherited as an autosomal recessive trait.