Genetic Screening and Double Mutation in Japanese Patients With Hypertrophic Cardiomyopathy

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Author(s)

    • KUBO Toru
    • Department of Medicine and Geriatrics, Kochi Medical School
    • OKAWA Makoto
    • Department of Medicine and Geriatrics, Kochi Medical School
    • BABA Yuichi
    • Department of Medicine and Geriatrics, Kochi Medical School
    • HAYATO Kayo
    • Department of Medicine and Geriatrics, Kochi Medical School
    • OTSUKA Haruna
    • Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University
    • ARIMURA Takuro
    • Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University
    • KIMURA Akinori
    • Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University

Abstract

<b><i>Background:</i></b> Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder with an autosomal-dominant pattern of inheritance mainly caused by single heterozygous mutations in sarcomere genes. Although multiple gene mutations have recently been reported in Western countries, clinical implications of multiple mutations in Japanese subjects are not clear. <b><i>Methods and Results:</i></b> A comprehensive genetic analysis of 5 sarcomere genes (cardiac β-myosin heavy chain gene [<i>MYH7</i>], cardiac myosin-binding protein C gene [<i>MYBPC3</i>], cardiac troponin T gene [<i>TNNT2</i>], α-tropomyosin gene [<i>TPM1</i>] and cardiac troponin I gene [<i>TNNI3</i>]) was performed in 93 unrelated patients and 14 mutations were identified in 28 patients. Twenty-six patients had single heterozygosity (20 in <i>MYBPC3</i>, 4 in <i>MYH7</i>, 1 in <i>TNNT2</i>, 1 in <i>TNNI3</i>), whereas 2 proband patients with familial HCM had double heterozygosity: 1 with P106fs in <i>MYBPC3</i> and R869C in <i>MYH7</i> and 1 with R945fs in <i>MYBPC3</i> and E1049D in <i>MYH7</i>. From the results of the family survey and the previous literature on HCM mutations, P106fs, R945fs and R869C seemed to be pathological mutations and E1049D might be a rare polymorphism. The proband patient with P106fs and R869C double mutation was diagnosed as having HCM at an earlier age (28 years of age) than her relatives with single mutation, and had greater wall thickness with left ventricular outflow obstruction. <b><i>Conclusions:</i></b> One double mutation was identified in a Japanese cohort of HCM patients. Further studies are needed to clarify the clinical significance of multiple mutations including phenotypic severity. (<i>Circ J</i> 2011; <b>75:</b> 2654-2659)<br>

Journal

  • Circulation Journal

    Circulation Journal 75(11), 2654-2659, 2011-10-25

    The Japanese Circulation Society

References:  22

Cited by:  5

Codes

  • NII Article ID (NAID)
    10030032426
  • NII NACSIS-CAT ID (NCID)
    AA11591968
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    13469843
  • Data Source
    CJP  CJPref  J-STAGE 
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