The buzz surrounds the idea of inhibiting myostatin either through gene therapy or via germline human genetic modification.
In this way, some hope to create people with more muscle. Myostatin, which also goes by the acronym MSTN, has an inhibitory function on muscle. Inhibit and inhibitor of muscle and you should get more muscle, right?
Data backs it up.
Animals including humans with spontaneous mutations in myostatin have unusual musculature including increases in muscle. This NEJM case report on a boy with a myostatin mutation describes a remarkable phenotype of drastically increased muscle and reduced fat. No clear pathology was associated with the condition, which is referred to as myostatin-related muscle hypertrophy. More on that condition more generally here.
Pop culture is fascinated with the idea of genetically modifying people to artificially create this kind of super-muscle condition. Would they be like superheroes? Just last week came the first report of a person, Liz Parrish, supposedly doing a DIY gene therapy to target myostatin.
If this kind of trend continues and increasingly involves people, what might go wrong? One possibility is that GM people who have had the myostatin pathway targeted could have other phenotypes or even diseases that we cannot anticipate.