The National Center for Case Study Teaching in Science has created this lesson plan to help young scientists understand contemporary scientific research and issues. Authored by Grace A. Farber of the University of Sciences and Amy T. Hark of Muhlenberg College, this lesson is designed to engage high school or college students with the CRISPR Cas9 system for genome editing. During this lesson, students read four interrelated case studies about different members of a single family. One of these individuals is a woman who hopes to conceive a child and meets with a genetic counselor after learning that she is a carrier for Duchenne Muscular Dystrophy (DMD). As students read through each case study, they explore supplemental activities that introduces them to how CRISPR gene editing works. Supplemental readings are scaffolded so that students examine increasingly complex resources with each case. These resources include a TED talk by Jennifer Doudna (one of the inventors of CRISPR technology), an article in Science Magazine, and research papers in Bioessays and Science. Instructors will need to have access to these supplemental materials as they are not included with the lesson plan.