'Life According to Sam' follows a teen with progeria Sam Berns is a bright, funny high school junior in Foxboro, Mass., who is about to turn 17. He loves math and science and plays percussion in the school's marching and concert bands. He and his father have seen the Dave Matthews Band so many times in concert, he's on a first-name basis with the group. "Junior year is fun and hectic at the same time," said Sam. I really enjoy being in classes and being in school with my friends. It's also cool to watch football games as a junior because a lot of my friends are now actually playing the game, and it's fun to watch them and root for them! But Sam isn't a typical teenager. He suffers from the progressive aging disorder progeria. It's so rare that when he was diagnosed with it at the age of 2, there were fewer than 250 children worldwide who had it. Progeria, also known as Hutchinson-Gilford progeria syndrome, is caused by a mutation in the LMNA gene. The gene produces the Lamin A protein, which, according to the Progeria Research Foundation, is the "structural scaffolding that holds the nucleus of a cell together." When the gene is defective, researchers believe, the nucleus is destabilized, leading to premature aging. Signs of progeria are growth failure, loss of body fat and hair, aged-looking skin and stiffness of joints. Whatever their ethnic background, the children who have it all have similar appearances, and most die of heart disease by the age of 13. The documentary "Life According to Sam," which opens theatrically Friday and airs Monday on HBO, chronicles the relentless pursuit by Sam's physician parents, Drs. Leslie Gordon and Scott Berns, to find a treatment and cure for their only child while striving to make sure he has as normal a life as possible. When Sam was diagnosed, his mother, who was then a resident, devoted herself to studying the disease, establishing the Progeria Research Foundation, headed by her sister, Audrey Gordon. "Life According to Sam," directed by Oscar winners Sean Fine and Andrea Nix Fine ("Inocente"), follows Gordon's launch of the first progeria drug trial, involving 26 children, including Sam, from 16 countries and her subsequent effort to get the results published in a peer-reviewed journal. When the married directors, who have two young sons, first met Sam and his family, "we were so moved by how positive they were because they have chosen not to accept no," said Andrea Nix Fine. After their first meeting, Nix Fine said, Sam told them, "I think we are all going to be very good friends here. There are other films that have been out there on progeria, and I don't want this film to be like those films. I don't ever want people to feel sorry for me. That is the one thing I am going to ask you guys. Gordon, said Sean Fine, had started the drug trials when filming began. "We thought the trial would be over in a year," he said. But we didn't realize how hard it is to get a scientific paper published. That made the film take three years. The filmmakers became very close to Sam during the production. "Sam is my friend," said Sean Fine. He's just a fun guy to hang out with. He's not a kid with progeria. Sam insisted on seeing the completed film by himself before his parents watched it. "I wanted to be able to process what was on screen and to be able to watch it and react without having to worry about other people's reactions at the same time watching it," he said in an email interview. I thought it was really interesting to see myself as a 13-year-old and go back and reflect on that version of myself, since I am now 16 years old. Sam hopes audiences will come away with a "positive and uplifting feeling. And, hopefully, they are inspired to help kids with progeria through the Progeria Research Foundation. At the same time, I hope they may be able to take away a couple of life lessons from the film, including the importance of friends and family as well as perseverance.