"The genetic legacy each of us inherits is a powerful force  and in a few extreme cases it can be deadly. Still thanks to science genetics need not always be destiny as Martha Teichner shows us in our Cover Story Amy and Brad Prices home in Omaha Nebraska is crazy with all the kids around. There are seven of them ages  to . But if you look closely youll see small memorials to one more Liviana who died in  at the age of  of a rare nightmare disease called late infantile metachromatic leukodystrophy. MLD destroys brain cells and is caused by a single faulty gene. She was happy all the time Brad said.  Amy added She loved pretty dresses.  She loved her tutu Brad said. She was talkative addicted to Caillou the animated TV series a lively little girl til she was two. Her knees were going a little knockkneed Amy said. And she had been just randomly falling down. Her doctor said Nothing to worry about but she quickly got worse.  I was in the kitchen doing something and I heard her crying Amy recalled. And I turned around and said Liviana whats wrong And she said Mommy my legs dont work. Liviana was diagnosed in the fall of . Amy recalled Shes sitting on the bed in her tutu and her colorful sweater and theyre telling me shes gonna die.  Many children with the disorder are dead by the age of . And it runs in families. If it hadnt been for Liviana Amy and Brad Price would never have known to have their other children tested. They learned that their infant son Giovanni had inherited the faulty gene too.  I get a call from the doctors office said Amy I knew. And I was thinking Ive just been told two of my kids now are gonna die. Except thats not what happened.  Doing research online Amy Price discovered the existence of a medical trial in Milan Italy of an extraordinary gene therapy treatment for MLD that would save Giovannis life  and later when his sister Cecilia was born with MLD hers too. The treatment works only on children who like them have not yet started showing symptoms.  The Price family scraped together the money to go to Milan. The patients go to the surgery room for collection of the stem cells on Monday and receive their cells back on Friday evening said Dr. Alessandra Biffi who oversaw the trial. A patients stem cells contain the faulty gene which the doctors have learned how to fix. Amazing right But then they need a vehicle to insert the good gene into the stem cells before those are put back into the patients body.  Heres whats really amazing That vehicle is the HIV virus reengineered so the children cant get AIDS.  Why the HIV virus Is it particularly efficient at getting around the body Teichner asked.  Yeah its very efficient in entering our cells and thats why we use it Dr. Biffi replied.  How well did the children do It will take years to know for sure but so far so good. At least  of them have an outstanding benefit coming from the treatment Dr. Biffi said. Some of the children were going to school and having a normal life. Giovanni Price is six now in first grade. He and his sister Cecilia Ceci for short have to go back to Milan twice a year to be tested and monitored. Brad Price calls Dr. Biffi Our angel. She took us in like family. So why Italy and not the United States  Gene therapy has a checkered history. In the s hyped as the Next Big Thing research withered here after serious setbacks including a death during clinical trials https But more than  years later its back. One sign Dr. Biffi is now head of the gene therapy program at DanaFarberBoston Childrens Cancer and Blood Disorders Center. Teichner asked Do you believe that gene therapy is finally coming into its own I think yes absolutely Dr. Biffi replied.  The MLD trial she thinks demonstrates whats possible  offering promise to the  million Americans who suffer from some  rare diseases. Trials for the experimental treatment Ceci and Giovanni Price received in Milan have not begun in the U.S. They are two of only  children in the world with MLD to receive it. Compare Giovanni to Calliope Joy Carr also six from Bala Cynwyd Pa. outside Philadelphia. She can turn her head a little. She can still smile and laugh. But thats about all. She was diagnosed at . For her parents college professors Patrick Carr and Maria Kefalis coming to terms with the disease was wrenching. Its decline in slow motion and thats difficult said Carr. I remember the social worker said Its good to try to cry in the shower to save it from your family and your children Kefalis said.  After more than a year of rage and grief Kefalis decided that she had to find some way of helping MLD children. It was too late for Cal but she was desperate to give her daughters life meaning.  Were not wealthy people she said. We didnt know very influential people who could write a big check for a million dollars. And so we said Well well start selling cupcakes. The Calliope Joy Foundation was formed in . Its been slow going but the money added up. And when Kefalis learned about the Italian trial and the fact that Amy Price had to keep going back to Milan with Giovanni and Ceci it was clear she would use the money to help families get to Italy. She sent me a picture of Giovanni playing in his front yard Kefalis said. Hes three months younger than Cal so he shouldve been as sick as Cal. He should have been on a feeding tube. He should be paralyzed. And I thought I gotta be a part of this. I need to help this happen again and again and again. Maria Kefalis has turned cupcakes into weapons of war  her war against MLD. Shes raised more than  and helped where she could but shes hit a wall. So far not a single gene replacement therapy has been approved by the FDA. The trial in Italy is closed to new patients. It could be years before any children with MLD will be allowed to receive the treatment in the United States. Now its just impatience Kefalis said. Now its like When do we get this here What will it take. Tell me what you need me to do. Until then she continues to fight her battles one cupcake at a time  the Price children Giovanni and Cecilia proof to her the war can be won.  Teichner asked Brad and Amy Price You keep using the word miracle. In what way is all of this a miracle Our sons still with us and Cecilia as well they replied. Thats the miracle.  Putting a face on rare incurable diseases https Sunday Morning   New hope for young patients with rare genetic disease https CBS Evening News   Hard cases Investigating rare  tough diseases https  Minutes"