Restrictive Cardiomyopathy Resulting from a Troponin IType 3 Mutation in a Chinese Family

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