Fibroblast growth factor 12 (FGF-12), also known as fibroblast growth factor homologous factors (FHF), is cytosolic proteins that is homologous to fibroblast growth factors but is not secreted. FGF12 modulates both cardiac Na+ and Ca+ channel by binding to the conserved proximal part of the C-terminal domain of voltage-gated sodium channels Nav1.5. However, a single missense mutation in FGF12-B (Q7R-FGF12) reduced binding to the NaV1.5 C-terminus, yielding a Brugada Syndrome phenotype.