Restrictive Cardiomyopathy Resulting from a Troponin I Type 3 Mutation in a Chinese Family

Objective To identify the pathogenic variant responsible for restrictive cardiomyopathy (RCM) in a Chinese family.
Methods Next generation sequencing was used for detecting the mutation and results verified by sequencing. We used restriction enzyme digestion to test the mutation in the family members and 200 unrelated normal subjects without any cardiac inherited diseases when the mutation was identified.
Results Five individuals died from cardiac diseases, two of whom suffered from sudden cardiac death. Two individuals have suffered from chronic cardiac disorders. Mutation analysis revealed a novel missense mutation in exon 7 of troponin I type 3 (TNNI3), resulting in substitution of serine (S) with proline (P) at amino acid position 150, which cosegregated with the disease in the family, which is predicted to be probably damaging using PolyPhen-2. The mutation was not detected in the 200 unrelated subjects we tested.
Conclusion Using next generation sequencing, which has very recently been shown to be successful in identifying novel causative mutations of rare Mendelian disorders, we found a novel mutation of TNNI3 in a Chinese family with RCM.