The study has several important implications, Taylor said. Recognition that the mutations adversely impact regulation of RNA could lead to targeted therapy to correct the problem. The mutation's location in the prion-like domain might also prove significant. Although the mutations in hnRNPA2B1 or hnRNPA1 appear to be rare, hundreds of other RNA-binding proteins have prion-like domains. Taylor said patients with unexplained neurodegenerative diseases may have mutations in these proteins.The study's first authors are Hong Joo Kim, Nam Chul Kim, Yong-Dong Wang and Jennifer Moore, all of St. Jude; and Emily Scarborough and Zamia Diaz, both of the University of Pennsylvania. The other authors are Kyle MacLea and Eric Ross, both of Colorado State University; Brian Freibaum, Songqing Li, Anderson Kanagaraj and Robert Carter, all of St. Jude; Amandine Molliex, formerly of St. Jude; Kevin Boylan, Aleksandra Wojtas and Rosa Rademakers, all of the Mayo Clinic, Jacksonville, Fla.; Jack Pinkus and Steven Greenberg, both of Brigham and Women's Hospital and Harvard Medical School; John Trojanowski, Bradley Smith, Yun Li and Alice Flynn Ford, all of the University of Pennsylvania; Bryan Traynor, of the National Institute of Aging, National Institutes of Health, Bethesda, Md.; Simon Topp, Athina-Soragia Gkazi, Jack Miller and Christopher Shaw, all of the Institute of Psychiatry, London; Michael Kottlors and Janbernd Kirschner, both of University Children's Hospital Freiburg, Germany; Alan Pestronk and Conrad Weihl, both of the Washington University School of Medicine, St. Louis; Aaron Gitler, Stanford University School of Medicine; Michael Benatar, University of Miami Miller School of Medicine; Oliver King, Boston Biomedical Research Institute, Watertown, Mass.; and Virginia Kimonis, University of California-Irvine. The research was supported in part by the Packard Foundation, by grants (NS053825, AG032953, DP2OD002177 and NS067354) from the National Institutes of Health, the ALS Association, the Ellison Medical Foundation, a grant (MCB-1023771) from the National Science Foundation and ALSAC.