Child born with extreme muscle growth

Superboy might lead science to new drugs
LINDA A. JOHNSON; The Associated Press
(Published June 24th, 2004)

Somewhere in Germany is a baby Superman, born in Berlin with bulging arm and leg muscles. Not yet 5, he can hold 7-pound weights with arms extended, something many adults cannot do. He has muscles twice the size of other kids his age and half their body fat.

DNA testing showed why: The boy has a genetic mutation that boosts muscle growth.

The discovery, reported in today's New England Journal of Medicine, represents the first documented human case of such a mutation.

Many scientists believe the find could eventually lead to drugs for treating people with muscular dystrophy and other muscle-destroying conditions. And athletes would almost surely want to get their hands on such a drug and use it like steroids to bulk up.

Drugmaker Wyeth, based in Madison, N.J., already has begun human tests of a genetically engineered drug designed to bind to and neutralize myostatin, said spokeswoman Natalie de Vane.

The boy's mutant DNA segment was found to block production of a protein called myostatin that limits muscle growth. The news comes seven years after researchers at Johns Hopkins University in Baltimore created buff "mighty mice" by "turning off" the gene that directs cells to produce myostatin.

"Now we can say that myostatin acts the same way in humans as in animals," said the boy's physician, Dr. Markus Schuelke, a professor in the child neurology department at Charite/University Medical Center Berlin. "We can apply that knowledge to humans, including trial therapies for muscular dystrophy."

Given the huge potential market for such drugs, researchers at universities and pharmaceutical companies already are trying to find a way to limit the amount and activity of myostatin in the body.

At Wyeth, de Vane said the company's first clinical trials of its antibody-based drug targeting the myostatin protein are testing whether it is effective against muscular dystrophy or sarcopenia, the loss of muscle mass and strength due to aging and diseases including cancer. The drug is known only as MYO-029 at this point.

Muscular dystrophy is the most common genetic disease. There is no cure and the most common form, Duchenne's, usually kills before adulthood. The few treatments being tried to slow its progression have serious side effects.

Muscle wasting also is common in the elderly and patients with diseases such as cancer and AIDS.

Dr. Se-Jin Lee, the Johns Hopkins professor whose team created the "mighty mice," said he believes a myostatin blocker also could suppress fat accumulation and thus thwart the development of diabetes.

Researchers would not disclose the German boy's identity but said he was born to a somewhat muscular mother, a 24-year-old former sprinter. Her brother and three other close male relatives all were unusually strong.

The boy is healthy, but doctors worry he could eventually suffer heart or other health problems.

Photo: http://www.tribnet.com/news/story/5226069p-5160430c.html