PurposeHypertrophic cardiomyopathy is the most common cause of sudden death in 
young people, including trained athletes, and is caused by mutations in genes 
encoding proteins of the cardiac sarcomere. Mutations in the Troponin C gene 
(TNNC1) are a rare genetic cause of hypertrophic cardiomyopathy. We describe a 
novel type of mutation (c.363dupG) in Troponin C, a rare form of hypertrophic 
cardiomyopathy.
METHODS: A family in which a 19-year-old asymptomatic male died of sudden 
cardiac death due to hypertrophic cardiomyopathy was genetically studied by 
sequencing 17 genes associated with hypertrophic cardiomyopathy or its 
phenocopies.
RESULTS: A c.363dupG mutation in Troponin C was identified, and tested across 
the family.
CONCLUSIONS: We report the first frameshift mutation (c.363dupG or 
p.Gln122AlafsX30) in Troponin C causing hypertrophic cardiomyopathy (and sudden 
cardiac death) in a 19-year-old male, and have demonstrated that the mutation 
segregates with hypertrophic cardiomyopathy within the family.