Diverse Phenotypic Expression of Cardiomyopathies in a Family with TNNI3 p.Arg145Trp Mutation.
- Author:
Ji Won HWANG
1
;
Mi Ae JANG
;
Shin Yi JANG
;
Soo Hyun SEO
;
Moon Woo SEONG
;
Sung Sup PARK
;
Chang Seok KI
;
Duk Kyung KIM
Author Information
- Publication Type:Case Report
- Keywords: Cardiomyopathies; TNNI3 mutation; Cardiomyopathy, hypertrophic; Cardiomyopathy, restrictive; Korean
- MeSH: Amino Acid Substitution; Cardiomyopathies*; Cardiomyopathy, Hypertrophic; Cardiomyopathy, Restrictive; Diagnosis; Female; Humans; Korea; Middle Aged; Phenotype; Population Characteristics; Sarcomeres; Siblings; Troponin I
- From:Korean Circulation Journal 2017;47(2):270-277
- CountryRepublic of Korea
- Language:English
- Abstract: Genetic diagnosis of cardiomyopathies is challenging, due to the marked genetic and allelic heterogeneity and the lack of knowledge of the mutations that lead to clinical phenotypes. Here, we present the case of a large family, in which a single TNNI3 mutation caused variable phenotypic expression, ranging from restrictive cardiomyopathy (RCMP) to hypertrophic cardiomyopathy (HCMP) to near-normal phenotype. The proband was a 57-year-old female with HCMP. Examining the family history revealed that her elder sister had expired due to severe RCMP. Using a next-generation sequencing-based gene panel to analyze the proband, we identified a known TNNI3 gene mutation, c.433C>T, which is predicted to cause an amino acid substitution (p.Arg145Trp) in the highly conserved inhibitory region of the cardiac troponin I protein. Sanger sequencing confirmed that six relatives with RCMP or near-normal phenotypes also carried this mutation. To our knowledge, this is the first genetically confirmed family with diverse phenotypic expression of cardiomyopathies in Korea. Our findings demonstrate familial implications, where a single mutation in a sarcomere protein can cause diverse phenotypic expression of cardiomyopathies.
