Mary Gates Endowment For Students

Linda Tran

Mary Gates Research Scholar, Autumn 2021

Research Project: Determining the Functional Significance of MYH7 Variants in Human Stem Cell-derived Cardiomyocytes

Project Description: Pathogenic missense mutations in the myosin heavy chain 7 (MYH7) gene are the most common genetic cause of hypertrophic cardiomyopathy. While several pathogenic variants have been modeled and studied extensively, the majority of MYH7 variants are classified as variants of unknown significance (VUS) in variant catalogs such as ClinVar, because they lack sufficient clinical and functional data for variant effect interpretation. To model and determine the functional significance of additional MYH7 VUS, I will employ gene-editing techniques to generate single variant repair templates for several VUS of interest in human induced pluripotent stem cells (hiPSC). Following heterozygous knock-in of a variant transgene into the endogenous MYH7 locus, I will differentiate hiPSCs into cardiomyocytes using established, efficient cardiac directed-differentiation protocols for comparison to wild-type hiPSC-derived cardiomyocytes across multiple metrics. Variant effect on contractile function will be measured in engineered heart tissues (EHTs). In addition, cardiomyocyte cell size will be measured across wild-type and variants using flow cytometry. This functional data will inform VUS interpretation as benign or pathogenic and provide healthcare professionals and patients with clinically actionable information.

What have you learned throughout your research project?

Throughout my project, I have learned that research is not a linear process. You will encounter setbacks before you find an approach that works. Through trial and error, new ideas and direction will provide the most efficient and optimized methods to make headway in your project and the field of science.

What piece of advice do you have for future applicants?

The most valuable experience of undergraduate research is the ability to interact with the community of mentors and professionals in your field of interest. Be eager to learn new techniques, ask fundamental questions and invest time into a project that you are passionate about. Research is about trial and error most of the time, so don’t be discouraged to fail more times than you succeed.