A toddler in Michigan has the muscles of an athlete. He is adopted, so his parentage is unknown. But he has a rare condition that promotes growth of the skeletal muscles. He has 40% more muscle mass than expected. He is strong and quick with a fast metabolism and almost no body fat. Liam has a rare genetic condition called myostatin-related muscle hypertrophy.
Myostatin-related muscle hypertrophy was documented in beef cattle and mice in the late 1990s. In 1997, researchers at Johns Hopkins University Hospital in Baltimore found that Belgian Blue cattle, an unusually muscular breed, had mutations in the gene that produces myostatin. Then they produced muscular mice by deactivating the rodent version of the myostatin gene and published their results.
Scientists are excited. They have located enough adults with this coondition to start a research study without needing Liam to take part. The research could lead to new treatments for debilitating ailments in which muscles deteriorate, such as muscular dystrophy and osteoporosis.
The first human case, in a German boy, was documented in 2000; but wasn’t reported in medical literature until 2004. Kathryn R. Wagner, a genetics expert at Johns Hopkins, says that it’s so rare that we don’t know how many people have it.
There are two kinds of myostatin-related muscle hypertrophy:
- In some people, a genetic mutation prevents the body from producing myostatin. Those individuals can have twice the normal amount of muscle mass.
- In others, like Liam, myostatin is produced but the muscle cells don’t take it in. People with his condition can have up to 50 per cent more muscle mass than the average person.
The result of both types of myostatin-related muscle hypertrophy generally are the same: above average growth of skeletal muscles, incredible strength, a warp-speed metabolism and minimal body fat.
For Liam, the condition has one potential drawback: Infants and toddlers need some body fat to feed brain growth and the development of the central nervous system.
Without adequate body fat, a child’s growth can be stunted and the central nervous system can be impaired, said Dr. Erlund Larson, an internist at Hackley Hospital who is familiar with Liam’s condition.
For Liam’s parents, the most pressing challenge is feeding the boy enough protein every day to fuel his body’s high-performance motor. The wiry but muscular toddler eats six full meals per day and still struggles to gain weight.
“If the myostatin protein is knocked out, muscles grow and rejuvenate much more quickly,” Dr. Larson said. “It has potential for great abuse in the future as the new steroid.”
Some body-building powders claim to have myostatin-blocking powers, but scientists say that they don’t.
Could a toddler like Liam have added to the Hercules legend? While still a baby, Hercules was said to have strangled a snake that came into his cradle.