title: Diverse Phenotypic Expression of Cardiomyopathies in a Family with TNNI3 p.Arg145Trp Mutation.
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.
authors.affiliation: Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Hwang
authors.affiliation: Department of Laboratory Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Mi-Ae
authors.initials: MA
authors.lastname: Jang
authors.affiliation: Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Shin Yi
authors.initials: SY
authors.lastname: Jang
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Seo
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Moon-Woo
authors.initials: MW
authors.lastname: Seong
authors.affiliation: Department of Laboratory Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sung Sup
authors.initials: SS
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Chang-Seok
authors.initials: CS
authors.lastname: Ki
authors.affiliation: Division of Cardiology, Department of Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Duk-Kyung
authors.initials: DK
authors.lastname: Kim
keywords: Cardiomyopathies; Cardiomyopathy, hypertrophic; Cardiomyopathy, restrictive; Korean; TNNI3 mutation