Studying Pathogenetic Contribution of a Variant of Unknown Significance, p.M659I (c.1977G > A) in MYH7, to the Development of Hypertrophic Cardiomyopathy Using CRISPR/Cas9-Engineered Isogenic Induced Pluripotent Stem Cells

Summary

Hypertrophic cardiomyopathy (HCM) is a cardiovascular pathology that is caused by variants in genes encoding sarcomere-associated proteins. However, the clinical significance of numerous variants in HCM-associated genes is still unknown. CRISPR/Cas9 is a tool of nucleotide sequence editing that allows for the unraveling of different biological tasks. In this study, introducing a mutation with CRISPR/Cas9 into induced pluripotent stem cells (iPSCs) of a healthy donor and the directed differentiation of the isogenic iPSC lines into cardiomyocytes were used to assess the pathogenicity of a variant of unknown significance, p.M659I (c.1977G > A) in MYH7, which was found previously in an HCM patient. Using two single-stranded donor oligonucleotides with and without the p.M659I (c.1977G > A) mutation, together with CRISPR/Cas9, an iPSC line heterozygous at the p.M659I (c.1977G > A) variant in MYH7 was generated. No CRISPR/Cas9 off-target activity was observed. The iPSC line with the introduced p.M659I (c.1977G > A) mutation in MYH7 retained its pluripotent state and normal karyotype. Compared to the isogenic control, cardiomyocytes derived from the iPSCs with the introduced p.M659I (c.1977G > A) mutation in MYH7 recapitulated known HCM features: enlarged size, elevated diastolic calcium level, changes in the expression of HCM-related genes, and disrupted energy metabolism. These findings indicate the pathogenicity of the variant.

Authors Pavlova SV, Shulgina AE, Zakian SM, Dementyeva EV
Journal International journal of molecular sciences
Publication Date 2024 Aug 9;25(16)
PubMed 39201382
PubMed Central PMC11354791
DOI 10.3390/ijms25168695

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