Muscle-bound boy result of gene mutation

By ANDREW GUMBEL

LOS ANGELES - When the baby boy emerged, midwives and doctors immediately knew he was special. The head looked normal, but the body was simply remarkable. With bulging biceps and rippling pecs this was a child like no other.

A transatlantic team of researchers quickly went to work to discover exactly how a baby could be born looking like he had been working out in the womb.

Now, with the still muscle-bound boy aged four and a half, it has delivered an astonishing report.

The wonder child, born in Germany, owes his awesome build to a gene mutation that could have exciting medical consequences - not just for aspiring Arnold Schwarzeneggers but also for sufferers of wasting diseases such as muscular dystrophy or certain kinds of cancer.

The boy, who has not been named, was born with a mutation that effectively silenced his myostatin gene, and researchers are now convinced this is what caused the spontaneous development of strong muscle tissue.

The correlation between the myostatin gene and muscle development had previously been noted in mice and cattle, but its possible effects on humans had remained a matter of speculation.

As long ago as 1997, the Institute of Basic Biomedical Sciences at Johns Hopkins university in Baltimore created a breed of "mighty mice" who were twice as muscular as their siblings as a result of having their myostatin gene knocked out.

Decades earlier, cattle breeders had stumbled upon a similar discovery by developing a strain of cattle called Belgian Blues - animals that produce roughly twice the muscle and only a fraction of the fat of normal herds. Researchers later found that they, too, had inactive myostatin genes.

The hope now, according to papers published in yesterday's New England Journal of Medicine, is that it will be possible to develop a line of drugs to deplete myostatin - possibly by developing antibodies capable of blocking it.

The Wyeth medical research laboratory in Massachussetts has already begun safety tests as a prelude to further research in this direction. The benefits could potentially be reaped across the medical spectrum, not just for sufferers of wasting diseases but also for patients recovering from major illnesses (heavy chemotheraphy courses, for instance, or lung or kidney diseases) who have lost a lot of muscle tissue as a result of inactivity and bodily exhaustion.

The lead researcher into the German Muscle Boy is Markus Schuelke, a pediatric neurologist at the Charite University Medical Centre in Berlin, who described in the paper the sense of wonder that the boy's birth instilled in all his colleagues.

"Everybody noticed," he said.

The newborn's muscle movements were jittery for the first two months of his life, and at first doctors thought he might be suffering from epilepsy. But then Dr Schuelke recalled the Mighty Mice research and contacted Se-Jin Lee at Johns Hopkins University. It turned out to be the right track.

The baby came from an unusually strong family. His mother had been a professional sprinter and her grandfather had worked as a builder hauling 300-lb curbstones off trucks.

DNA tests revealed that the mother was missing one of her two myostatin genes, and that the boy was making no myostatin at all.

Further family research was not possible because nobody else agreed to submit to testing. Now close to school age, the boy remains noticeably stronger than his peers. Dr Schuelke reported that he was able to hold two 6.6-lb weights horizontally with his arms extended.

For the moment, no ill effects on his heart or other vital organs have been detected, although Dr Schuelke's research team is continuing to keep a close eye on him.

His case also raises the question of whether athletic prowess might to some extent be determined by myostatin levels in the rest of us.

Could the effectiveness of the gene determine how easy it is to add muscle tissue at the gym? Should professional athletes be tested for myostatin levels to determine how far they can enhance their performance? Might a whole new generation of sports-related drugs be in the offing?

"Myostatin blockade will probably work its way into professional and amateur athletics, as well as into the ever-growing business of physical enhancement," Dr Elizabeth McNally of the University of Chicago wrote in the New England Journal.

"Although the ethics of using such genetic information is questionable, the feasibility of identifying this information should not be doubted."

- INDEPENDENT