Since two mutations (R204C and R204H) at residue 204 of cTnI are associated with FHC and most mutations associated with FHC show increased Ca2+-sensitivity of force development (Xu et al., 2010), we hypothesized that any mutations at cTnI R204 would cause significant increases in Ca2+-sensitivity of force development. Here, TNNI3 is linked to hypercholesterolemia, familial, 1.