gahl's desk. they have accepted a little over 300 patients. >> you have to tell a lot of people no. >> we do, yes. >> it seems like that would be hard. >> it is hard. it's very hard. i have to take sol las in the fact we have helping a chosen few. >> the few with conditions no one can diagnose. chi lee dawn was born in may, 2004. the picture of a perfect baby girl. she developed like a healthy toddler. >> she was above average on everything. she could say her abcs when she was 18 months old. >> then at three and a half, she was diagnosed with type i diabetes. shortly after that, they noticed something wasn't right. it began with a voice tremor. >> i have to eat. >> then she had a siezure. by the time she turned 4, her face started to twitch. >> does your face feel funny? >> no. >> the first day you realized something wasn't right with her. she was a precocious child, zooming past the milestones. you are a parent saying is this me being overly sensitive. >> i was told that. i was looking for things

in fact, gahl and his team treat their patients like a crime scene. collect all the evidence they can find and then try to make sense of it. >> what we do like to sort of detective work, but, remember, a lot of the detective work takes place after the patients have gone. >> but that decision to take the sample of muscle tissue from sally's bicep, in time, that will prove to be a key part of this puzzle. so you're probably wondering how do all these clues come together? is it solvable? ahead, we'll have the conclusion of this medical mystery. :tv] [humming] ooh! here we go. announcer: you don't have to be perfect to be a perfect parent, because kids in foster care don't need perfection. they need you. t t adwiwiout food al >>> topping our medical news headlines, a decision about a popular diabetes drug linked to concerns about heart problems. the fda decided this week that avandia should be restricted to patients who can't control their diabetes with other medications. gsk or glaxosmithkline has responded saying the company continues to believe that av

gahl mention, anderson, they can accept failure. doctors usually with good at accepting failure but they know sometimes they can't find the answer but no those cases they have to move on and try to advance science so it's a totally different way of looking at things. >> this is the first of four parts we're airing this week. what about tomorrow? >> sally and kiley are part of the chosen few as was mentioned. one of a few hundred patients. now they've been accepted to the program. we'll give you a look at the process and take a peek behind the curtain and get a sense of what happens at a place like this. here's a little glimpse. kiley will undergo a week-long series of complex tests and evaluations by top medical specialists at nih. it's physically draining for everyone. and for kiley's mom and dad, emotionally wrenching. the week is intense. >> i don't think anybody has seen anything quite like kiley. this is a very complex case and could be difficult to solve. >> wow! we'll be learning along with the doctors, or try to learn, at le

gahl mention, anderson, they can accept failure.t usually good at accepting failure, but they know that sometimes they're not going to find the answer and in those cases they've still got to move on and try to see if they can advance science still. it's a totally different way of looking at things. >> this is the first of four parts that are going to be airing this week. what about tomorrow? >> sally and kylie are part of the chosen few, as was mentioned there, just one a few hundred patients. now they've been accepted to the program. what we're going to do is give you a look at the process, really take a peek behind the curtain and get a sense of what happens at a place like this. here's a little glimpse. >> can you swing, kylie? okay. >> kylie will undergo a week-long series of tests and evaluations by top medical specialists at nih. it's physically draining for everyone. and for kylie's mom and dad emotionally wrenching. >> you have feelings but -- >> reporter: the week is intense. >> i don't think anybody's seen anything quite l

william gahl is the program's lead investigator. >> when you see these pictures, they are incredible. you think steroids? >> sure. we pretty much all thought it, except the letter said she's not taking steroids, she's not taking anything anabolic, and she did weight lift a little bit but many years before. so there's no possible effect of that. so the endocrinologist had eliminated all the things we naturally would think about. >> when she falls asleep she tightens up some. >> reporter: dr. gahl and the udp see only the rarest cases. >> there's still a fair amount of rigidity. >> not only do they want to save lives, but they also want to advance science by identifying new diseases. >> bottom line, bone's not involved. it's not acromegaly. just confined to the muscle. what in the world could this be? >> reporter: during a week of intense tests, there are scans, blood work, an examination of everything going on inside sally's body. >> so this is sally's mri of the brain. that's pretty incredible. >> when the images were found, it was seen that the muscles, even the muscles that govern t

gahl was going to be like him.of money on test, although he has them available to him. but he understands the value of hope. and a lot of patients come here who haven't had any hope in quite some time but he also has to balance that with failure. again, this idea that he's not going to be able to figure everything out. it's not a happy ending at the end of every single episode. so it's some of the most candid frank conversations he has to have with patients an me as well. >> for a lot of patients, as we were investigating this, really got the sense that this ends up being a place of last hope or last rae sort for them. because a lot of them have been to some of the best places around the country fshl, if not world. and now they've got it all hingingen on this place. that's a lot of pressure. >> it is. we try to be realistic about it. and get our patients to be realistic about the issue, too. so the first day of a typical visit, i'll go in and tell the patients you know, you've been to the best places in the country