Based on 1 of the 6 gene mutations with the worst clinical phenotype for RCM, we have generated gain‐of‐function transgenic mice modeling mutations in human cTnI C‐terminus, cTnI R192H, by cardiac specific expression of the mutated protein in mouse heart (cTnI193His in mouse sequence). This evidence concerns the gene TNNI3 and cardiomyopathy, familial restrictive, 1.