Experts at Nationwide Children's Hospital have developed a novel Titin-deficient mouse, TTN 219, in order to study limb girdle muscular dystrophy type 2J (LGMD2J) based on a documented patient mutation. The TTN219 mouse model was developed using CRISPR/Cas9 technology therefore the time required to modify the Titin gene is reduced as well as off-target insertions into the mouse genome. Our experts have demonstrated functional deficits in skeletal muscles of the TTN219 mouse model and plan to use this model to test therapeutic strategies intramuscularly and systemically to restore Titin protein function.