Deletion in TNNI3 gene is associated with restrictive cardiomyopathy

In dilated and hypertrophic cardiomyopathies, over ten disease-causing genes have been identified in each entity. In contrast, mutations in only desmin and cardiac troponin T and I ( TNNI3) have been shown to cause restrictive cardiomyopathy ( RCM). We applied a candidate gene approach and identified a novel one nucleotide deletion, resulting in frame shift and predicted formation of a premature stop codon, deletion of part of exon 7 and all exon 8, and truncation of significant C-terminal portion of TNNI3. Western blot analysis showed approximately 50% reduction of total troponin I content in myocardial tissue. The clinical hallmark was a restrictive type of cardiac hemodynamics, and congestive heart failure, leading to the death of the patient at the age of 28.