GAA and hypertrophic cardiomyopathy: Here, we report the successful generation of a Gaac.1826dupA (p.Y609*)14 murine knock-in model of Pompe disease utilizing a novel, dual-single guide RNA approach flanking the intended Gaa insertion site, and early characterization that demonstrates GAA enzymatic deficiency, hypertrophic cardiomyopathy, muscular glycogen storage and pathology recapitulating human Pompe disease.