But a high metabolism is hardly a deterrent for doctors, scientists, or some body builders, seeking a way to build muscle mass.
Doctors at the University of Pennsylvania -- another strong institution for muscle research -- have already been contacted by the World Anti-Doping Agency to develop ways to detect so-called gene doping.
"In the lab the answer is absolutely yes, you can tell if someone has been doping [with the known myostatin blockers]. But the question is would it pass muster in a regulatory fashion," said Tejvir S. Khurana, an associate professor of physiology at the University of Pennsylvania and the Pennsylvania Muscle Institute in Philadelphia.
Studying myostatin and its effects on muscles is so new that Khurana, Lee and Wells are all unsure of the potential negative health consequences of gene therapy, or gene doping.
John Faulkner, a professor of physiology and biomedical engineering at the University of Michigan in Ann Arbor, has seen some negative effects of low myostatin in mice.
"It's a proverbial two-edge sword. It's beneficial if you want large muscles, but the problem is that the tendons don't develop along with it," he said.
In mice, at least, Faulkner has found tendons grow to be brittle and too small to hold huge muscles. But it's unclear if the same effect would happen in humans.
"In humans, we have no idea," said Lee.
Although Liam may be a normal boy in every other sense of the word, he may also show doctors the long-term effects of super strength.