SHANGHAI: Unlike other boys his age, 7-year-old Chen Jiakun is extremely quiet and never moves suddenly.

Chen Jiakun, a seven-year-old boy from east China's Shandong province yawns as his exposed heart is seen in a local hospital's ward in Shanghai June 20, 2006. Chen is in danger because his heart is only protected by his skin. According to the hospital, the boy is also suffering five other heart diseases called "Cantrell's pentalogy" , a rare syndrome characterized a deficiency of the anterior diaphragm, a midline supraumbilical abdominal wall defect, a defect in the diaphragmatic pericardium, congenital intracardiac abnormalities, and a defect of the lower sternum. [newsphoto]

He can't run. He can't jump. Even crying is dangerous for Chen he does not have a sternum or muscles that protect his heart.

The boy from East China's Shandong Province was born with a very rare syndrome called "pentalogy of Cantrell." Soon, doctors at Shanghai Children's Hospital will perform a complicated surgery to give him a chance at a normal life.

The disease, only reported once in China, means the boy suffers from a complex constellation of defects including congenital heart disease and sternum abnormalities.

In front of Chen's chest is a large mass containing his heart and intestines. People can see and feel how his heart is beating under the skin. The mass swells and throbs if he moves quickly. And coughing will cause it to grow to 15 centimetres long--almost three times its usual size.

Since birth, respiratory infections and pneumonia have haunted Chen frequently, and he grows much more slowly than healthy children. He cannot go to school, because teachers are afraid that any small injury to his vulnerable heart might threaten his life.

"We took him to several local hospitals and a hospital in Beijing, but doctors said they were unable to treat such a rare case," said the boy's father, Chen Xiaojun.

Medical costs are expensive for the peasant family from the mountains. Chen's 16-year-old brother had to travel to the cities to earn money after he finished middle school. But the family says they will never give up on Chen's treatment.

"We would sell our house to raise money for my son," the boy's father said.

Thanks to the generosity of some warm-hearted people, including a couple from Taiwan Province, the boy was sent to Shanghai Children's Hospital, a leader in treating difficult diseases in China.

"A team of around 10 medical staff will perform the surgery. The surgery is challenging, but we are confident," said professor Jia Bing, the chief surgeon.

To repair Chen's defective sternum, surgeons will cut a layer of the existing sternums on both sides, then slide them into the middle of the chest.

"This therapy is less risky and causes less harm than implanting artificial materials," Jia said.

The same "separate and slide" method will be used on abdomen muscles to repair defective chest muscles. Since the hole in his heart is very small, Chen does not need heart surgery.

The surgery will take 5 hours, and the total cost will be less than 80,000 yuan (US$10,000) -- much cheaper than the 1 million yuan (US$125,000) required by a German hospital.