NRAS and Miyoshi myopathy: Two studies demonstrated a high incidence of NRAS and KRAS activating mutations: one of them reported these mutations at codons 12, 13, or 61 in 27% of pPCL and 15% of sPCL cases [8], and in the other study NRAS and/or KRAS mutations were found in 50% of pPCL cases and in 55% of MM [20].