A study led by St. Jude Children’s Research Hospital has discovered mutations in two genes that lead to the death of nerve cells in amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, and related degenerative diseases.The same mutation occurred in both genes and led to the abnormal build-up of the proteins inside cells. These proteins play an essential role in normal RNA functioning and have also been linked to cancer, including the Ewing sarcoma, the second most common type of bone cancer in children and adolescents. The finding is the latest in a series of discoveries suggesting degenerative diseases and cancer may have common origins. RNA is the molecule that directs protein assembly based on instructions carried in DNA.