GGPS1 Mutation and Atypical Femoral Fractures with Bisphosphonates. Submitted by jdopazo on Tue, 09/26/2017 - 10:39 Roca-Ayats N, Balcells S, Garcia-Giralt N, et al. GGPS1 Mutation and Atypical Femoral Fractures with Bisphosphonates. N Engl J Med. 2017;376(18):1794-1795. doi:10.1056/NEJMc1612804.