Cardiac phenotype characterization at magnetic resonance imaging in alpha-protein kinase 3–associated hypertrophic cardiomyopathy

Figures

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  Fig. 1. Study flowchart. A total of 592 patients diagnosed with hypertrophic phenotypic cardiomyopathy were referred for genetic testing. Seventeen patients were excluded from the analysis, including four patients with LAMP2 pathogenic variants, six patients with GLA pathogenic variants, three patients with PRKAG2 pathogenic variants, and four patients with GAA pathogenic variants. Consequently, 575 patients were included in the final analysis. Among these, 37 patients were identified as carriers of heterozygous ALPK3 variants, including 17 patients who also carried other HCM–related sarcomeric gene variants. ALPK3 alpha-protein kinase 3, LAMP2 lysosome-associated membrane protein 2, GLA galactosidase alpha, PRKAG2 protein kinase AMP-activated non-catalytic subunit gamma 2, GAA acid alpha-glucosidase

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  Fig. 2. A 36-year-old female patient was diagnosed as showing HCM (ALPK3 truncating variants, mutation site: c.2200A>T). (a-d) Two-chamber (a, b) and four-chamber (c, d) cine images at end-diastole and end-systole showed severe symmetric apical hypertrophy (pure ApHCM); (e-f) LGE images demonstrated no fibrosis; (g-h) T1 maps showed the increased native T1 (g) and ECV (h). 2ch two-chamber, 4ch four-chamber, ALPK3 alpha-protein kinase 3, ECV extracellular volume, end-dia end-diastole, end-sys end-systole, LGE late gadolinium enhancement, SAX short axis

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  Fig. 3. A 27-year-old male was diagnosed as showing HCM (ALPK3 truncating variants, mutation site: c.715delC). (a-d) Two-chamber (a, b) and four-chamber (c, d) cine images at end-diastole and end-systole showed left ventricular severe symmetric apical and septal hypertrophy but with the thickest apex (mixed ApHCM) and right ventricular hypertrophy (asterisk); (e-f) LGE images demonstrated left ventricular diffuse fibrosis predominantly in apex-lateral wall, along with right ventricular patchy fibrosis (red arrow); (g-h) T1 maps showed increased native T1 (g) and ECV (h). 2ch two-chamber, 4ch four-chamber, ALPK3 alpha-protein kinase 3, ApHCM apical hypertrophic cardiomyopathy, ECV extracellular volume, end-dia end-diastole, end-sys end-systole, HCM hypertrophic cardiomyopathy, LGE late gadolinium enhancement, SAX short axis

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  Fig. 4. A 53-year-old male was diagnosed as showing HCM (ALPK3 truncating variants, mutation site: c.5290C>T). (a-d) Two-chamber (a, b) and four-chamber (c, d) cine images at end-diastole and end-systole showed severe symmetric apical and septal hypertrophy but with the thickest apex (mixed ApHCM); (e-f) LGE images demonstrated no fibrosis; (g-h) T1 maps showed the increased native T1 (g) and ECV (h). 2ch two-chamber, 4ch four-chamber, ALPK3 alpha-protein kinase 3, ApHCM apical hypertrophic cardiomyopathy, ECV extracellular volume, end-dia end-diastole, end-sys end-systole, HCM hypertrophic cardiomyopathy, LGE late gadolinium enhancement, SAX short axis