Incredible Bulk

There must be an advantage to myostatin, the gene that keeps our muscle bulk in check. But right now, it looks like there's a lot of upside in life without myostatin. Blocking myostatin could be great for astronauts, cancer and AIDS patients, and people too busy to work out. Just look how ripped this myostatin-negative boy is (NEJM, subscription required). Pics of him as an infant are reprinted at Apostropher. Now age five, he is more than seven standard deviations above age-matched boys for quadriceps CSA.

Will we learn someday that Schwarzenegger, Charles Atlas, or other bodybuilders / athletes were myostatin mutation heterozygotes (carriers)? After all, the boy's mother is, and she was a professional athlete herself. Will athletic regulators have to look out for a new class of performance-enhancing substances? It might depend on what cardiomyopathy or bony abnormalities awaits this young boy. His vigilant doctors have found no cause for concern, yet.

UPDATE: Medpundit looks at the boy's pedigree chart and surmises, "one night stand." But she says it more poetically, I think.

UPDATE: A breathtaking overinterpretation of this story is underway at Gene Expression. But at least some of it is grounded in the historical context of gene therapy for muscle wasting -- a topic I recall fondly. What's so encouraging about this myostatin news isn't that we can knock out genes to create superhumans (!) -- it's that this protein regulates notoriously hard-to-fix structural proteins, and since it's secreted, it can be easily blocked. If you've seen cachexia or Duchenne's, this news is plenty to get excited about -- even without our tendency to invoke Marvel superheroes.

UPDATE: CNN has picked up the story, and there are more comments and links at Metafilter. I mentioned this at the gym today, thinking they might be interested. I told him how Wyeth was working on antibodies to myostatin. The Supplement Man was not impressed, and directed me to MyoZap and said it's been available for a while now, "and does whatever those drug companies are trying to do." Funny, it's not on our hospital's formulary...