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Investigating the Pathogenesis of MYH7 Mutation Gly823Glu in Familial Hypertrophic Cardiomyopathy using a Mouse Model
Published on: August 8, 2022
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Genotype-Phenotype Correlations in Apical Variant Hypertrophic Cardiomyopathy
Eric C Towe1, J Martijn Bos2, Steve R Ommen3
1Department of Pediatrics, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minn, USA.
Congenital Heart Disease
|December 16, 2014
Summary
Apical hypertrophic cardiomyopathy (HCM) is rare, with most patients testing negative for genetic mutations. The most common HCM-related gene mutations, MYBPC3 and MYH7, were still prevalent in those with apical disease who tested positive.
Area of Science:
- Cardiology
- Genetics
- Medical Diagnostics
Background:
- Hypertrophic cardiomyopathy (HCM) presents diverse phenotypes and genotypes.
- Echocardiography classifies HCM into four subtypes: reverse curve, sigmoidal, neutral contour, and apical.
- The apical variant of HCM is less understood regarding its genetic basis and prevalence.
Purpose of the Study:
- To investigate the spectrum of mutations and genotype-phenotype correlations in apical HCM.
- To determine the prevalence and characteristics of apical HCM within a large cohort undergoing genetic testing.
Main Methods:
- 1053 patients with HCM underwent sarcomeric genetic testing between 1999 and 2007.
- Echocardiograms were analyzed for septal morphology, and phenotyping was done via medical records.
- Subset analysis focused on the genotype, phenotype, and outcomes of apical HCM patients.
Main Results:
- Apical HCM was identified in 7% of patients (71 individuals), with a mean wall thickness of 19.8 mm.
- Only 25% of apical HCM patients had a positive genetic test, predominantly for MYBPC3 and MYH7 mutations.
- No significant difference in adverse events was observed between genotype-positive and genotype-negative groups.
Conclusions:
- Apical HCM is an uncommon subtype (<10%) associated with negative genetic test results in 75% of cases.
- Contrary to some prior findings, MYBPC3 and MYH7 mutations were most common in genetically positive apical HCM patients.
- This study provides insights into the genetic landscape of apical HCM, highlighting MYBPC3 and MYH7 as key genes.
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