Muscles make up nearly 40% of the human body and power every move we make, from a child’s first steps to recovery after injury. For some, however, muscle development goes awry, leading to weakness, delayed motor milestones or lifelong disabilities. New research from the University of Georgia is shedding light on why.

UGA researchers have created a first-of-its-kind CRISPR screening platform for human muscle cells, identifying hundreds of genes critical to skeletal muscle formation and uncovering the potential cause of a rare genetic disorder. The findings come from two companion papers published in Nature Communications, one describing the large-scale screen and a second digging into a particular gene’s role in muscle development.

Together, the studies provide a comprehensive genetic map of how human muscle fibers are built and lend insights into the effects of genetic mutations on developmental muscle defects. By linking specific genes to the muscle-building process, this genetic roadmap gives clinicians a practical shortlist to more quickly pinpoint the likely genetic causes of a patient’s muscle-development disorder. It also provides researchers with clear targets to prioritize future drug or gene therapy approaches.