TTN and idiopathic dilated cardiomyopathy: Recently, a large study of 312 subjects with dilated cardiomyopathy, 231 subjects with hypertrophic cardiomyopathy, and 249 controls, using next-generation sequencing, identified TTN truncating mutations and mutations predicted to alter titin structure as a common cause of dilated cardiomyopathy, occurring in approximately 25% of familial cases of idiopathic dilated cardiomyopathy and in 18% of sporadic cases [26].