Both acquired and inherited disorders of muscle are common; thus, greater understanding of
muscle growth and maintenance is important for future therapies. Myostatin down-regulates
muscle growth. These investigators describe a mutation in the gene for myostatin in a child
with muscle hypertrophy and unusual strength.

to the editor: Schuelke et al.(June 24 issue) 1 describe a child with muscle hypertrophy in
association with a mutation in the myostatin gene. Another possible case of a myostatin
mutation in an exceptionally strong child was described more than 2500 years ago in Greek
mythology, in the story about Hercules. As an infant, Hercules strangled a snake in each
hand when the goddess Hera tried to kill him. His legendary strength was obvious from the
time of his birth, and it was not the result of any exercise program.