SCN9A and paroxysmal extreme pain disorder: We performed in-silico mutagenesis for 18 mutations causing IEM, 6 mutations causing SFN, 6 mutations causing PEPD (Additional file 2: Table S1), 4 mutations not causing biophysical abnormalities (nABN) in the channel (N1245S: [53]; L1267V: [53]; V1428I and T920N: Waxman, Dib-Hajj and Mantegazza, unpublished observations) and 49 SNPs identified among human and homologous mammalian (hSNPs) SCN9A genes with >90% sequence identity (Additional file 5: S2 Text).