Myostatin deficiency refers to an abnormal growth condition in which myostatin, the protein responsible for controlling muscle growth, is either missing from the body or has been deactivated. Without fully functioning myostatin proteins in the body, muscles are free to grow without restriction. This, therefore, leads to a state of muscular hypertrophy, in which the muscles of the body grow to an abnormal size.
A gene called MSTN controls myostatin production and activation. Each cell in the body has two instances of this gene. As little as one mutation in one instance of the gene can cause myostatin deficiency by disrupting the way in which the body produces or uses myostatin. If both instances of the MSTN gene in each cell are mutated, then the muscular hypertrophy is typically more severe.
The mutations in the MSTN gene can lead to myostatin deficiency in one of two ways. In some instances, the instructions concerning the production of myostatin become equally mutated or corrupted, leading cells in the body to either produce little or no myostatin at all. Other times, the instructions regarding the proper use of myostatin become corrupted. In this instance, there may be plenty of myostatin proteins available within the cells, but they merely sit idly by because they have not been instructed by the body to do anything.
At of 2010, there was no clinical treatment for myostatin deficiency. Case studies on animals such as mice and cattle have revealed that the muscle growth that results from a lack of myostatin never exceeds 40 percent. Myostatin functions the same in humans as it does in animals, so myostatin deficiency isn’t fatal. Only a very minute portion of the popular suffers from myostatin deficiency. This includes babies and a select few professional bodybuilders.
Though myostatin deficiency is an unwanted condition by itself, researchers hope to use the science behind it to one day cure muscular dystrophy. By injecting into the body substances that block myostatin, the hope is that the weakened muscles of muscular dystrophy will grow to their normal size. There is, however, a concern that such a solution could inevitably cause the disease to worsen in the future.
At the same time, the idea of using myostatin blockers to promote muscle growth in bodybuilders has also been considered. Any such possibility would, however, require intense testing by the FDA before being released into the mainstream market. It also could face regulation by the governing bodies of the competitive bodybuilding industry.