Provided herein are variant adeno-associated virus (AAV) capsid proteins having one or more modifications in amino acid sequence relative to a parental AAV capsid protein, which, when present in an AAV virion, confer increased infectivity of one or more types of muscle cells as compared to the infectivity of the muscle cells by an AAV virion comprising the unmodified parental AAV capsid protein. Also provided are recombinant AAV virions and pharmaceutical compositions thereof comprising a variant AAV capsid protein as described herein, methods of making these rAAV capsid proteins and virions, and methods for using these rAAV capsid proteins and virions in research and in clinical practice, for example in, e.g., the delivery of nucleic acid sequences to one or more muscle cells for the treatment of muscle disorders and diseases.
