Genetic mutation turns tot into superboy
4-year-old is first documented human case, scientists say
New England Journal Of Medicine / AP File A German boy, seen
here at seven-months old, has a genetic mutation that boosts
muscle growth.
The Associated Press BOSTON - Somewhere in Germany is a
baby Superman, born in Berlin with bulging arm and leg
muscles. Not yet 5, he can hold seven-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 Thursday'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. 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. We can apply that knowledge to humans,
including trial therapies for muscular dystrophy.'
- DR. MARCUS SCHUELKE
Charite/University Medical Center Berlin"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. Wyeth has just begun human tests of a
genetically engineered antibody designed to neutralize
myostatin.
Ds. Lou Kunkel, director of the genomics program at Boston
Children's Hospital and professor of pediatrics and
genetics at Harvard Medical School, said success is
possible within several years.
"Just decreasing this protein by 20, 30, 50 percent can have
a profound effect on muscle bulk," said Kunkel, who is among
the doctors participating in the Wyeth research. Slow
wasting process
Muscular dystrophy is the world's 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.
"If you could find a way to block myostatin activity,
you might slow the wasting process," said Dr. Se-Jin
Lee, the Johns Hopkins professor whose team created the
"mighty mice."
Lee said he believes a myostatin blocker also could suppress
fat accumulation and thus thwart the development of
diabetes. Lee and Johns Hopkins would receive royalties for
any myostatin-blocking drug made by Wyeth.
Dt. Eric Hoffman, director of Children's National Medical
Center's Research Center for Genetic Medicine, said he
believes a muscular dystrophy cure will be found, but he
is unsure whether it will be a myostatin-blocking drug,
another treatment or a combination, because about a
dozen genes have some effect on muscles.
He said a mystotatin-blocking drug could help other groups
of people, including astronauts and others who lose muscle
mass during long stints in zero gravity or when immobilized
by illness or a broken limb.
Eventual health problems?
Researchers would not disclose the German boy's identity but
said he was born to a somewhat muscular mother, a 24-year-
old former professional sprinter. Her brother and three
other close male relatives all were unusually strong, with
one of them a construction worker able to unload heavy
curbstones by hand.
In the mother, one copy of the gene is mutated and the other
is normal; the boy has two mutated copies. One almost
definitely came from his father, but no information about
him has been disclosed. The mutation is very rare in people.
The boy is healthy now, but doctors worry he could
eventually suffer heart or other health problems.
In the past few years, scientists have seen great potential
in myostatin-blocking strategies. Internet marketers have
been hawking "myostatin-blocking" supplements to
bodybuilders, though doctors say the products are useless
and perhaps dangerous.
Some researchers are trying to turn off the myostatin gene
in chickens to produce more meat per bird. And several
breeds of cattle have natural variations in the gene that,
aided by selective breeding, give them far more muscle and
less fat than other steer.
© 2004 The Associated Press.
A professor asked a student, "If you had a choice between
the oppressed and the oppressor which would you choose." The
student replied, "Neither". The Professor shook his head and
stated, "You don't have a choice." The student paused and
said, "The oppressed".