TODAY | September 06, 2013
>> on our series the age of alzheimer 's we have been examining the impact it's having on all of us. maria shriver has been reporting on it for years. she brings us a hopeful story.
>> it's estimated that more than 5.5 million americans are living with alzheimer 's disease and by the middle of the century the number could grow to 16 million. the causes are relatively unknown and today there's no cure but there is anticipation that a way to slow down or even stop the disease may be found in a way that may surprise you.
>> ben is not your average 22-year-old overachiever. ben is a resource specialist at massachusetts general hospital 's down syndrome process run by the world renowned researcher.
>> you have a great heart.
>> for years down syndrome and alzheimer 's researchers have known there was a link between the two conditions but only now are scientists investigating the link together.
>> the timing has never been better for people with with down syndrome and for the rest of us. we are unlocking the mysteries between down syndrome and alzheimer 's disease.
>> here's the connection. every person with down syndrome has more of a protein that's found in the brains of people with alzheimer 's. a protein that leads to the plaque that destroy brain cells .
>> the plaques are encoded by the 21st chromosome and people with down syndrome have an extra dosage so they produce more of the plaques and they start to accumulate in the brains of them since childhood.
>> so they develop alzheimer 's earlier than others but only 50% of people with down syndrome by the age of 50 will actually develop the debilitating symptoms of alzheimer 's, such as dementia.
>> the provocative question is why do some develop it and why some do not.
>> what is the answer?
>> we don't know yet but researchers are trying to unlock the clues and the friends with down syndrome may unlock it for the rest of us.
>> what is protecting them that have the pathology in their 50s.
>> she is one of the top alzheimer 's researchers that now joined with down syndrome experts to come up with an answer. but studying people with down syndrome hasn't always been easy because parents are very protective.
>> there's been very few studies and this is a population that is very protected and it's been very difficult to get access to individuals. the down syndrome community has been fairly isolated.
>> before we test drugs in children, we test them out first on adults.
>> he is about to begin clinical trials of medicines that might improve cognition and possibly delay long-term memory loss.
>> so we'll give them four weeks of taking this medicine.
>> the trials will be closely watched by alzheimer 's researchers and by the doctor whose sister also has down syndrome .
>> i wouldn't be doing what i am today had it not been for my sister kristen.
>> would you suggest your sister be part of this.
>> it's an individual decision.
>> she hasn't made up her mind, yet?
>> she hasn't. no.
>> will ben sign up? his dad says they'll weigh the risks and rewards but the decision lays with ben .
>> we think he is perfect now so we don't look for changes in him but it makes you think more about if there's a potential for the cure and if this can unlock code to alzheimer 's we have to think about it for carefully.
>> does alzheimer 's scare you?
>> my fwrand mother had it so it scares me greatly. i think about what happens if i get alzheimer 's. so it requires us to do more planning.
>> there are many kinds of research now going on to defeat alzheimer 's in addition to that one on down syndrome . scientists are studying imagines of the brain and looking at proteins in the blood and the impact of vitamins and drugs. there's a lot going on that people are hopeful about. they want to stress that there is hope even though there isn't a cure today.
>> this has been such an amazing series as we reach the end of the week here. what's your big take away for people watching all week and whose family maybe dealing with alzheimer 's?
>> the numbers are only growing. so people have to start to get really angry. we have elections coming up so people can remember that their vote -- they can vote for people that have this in their platform or who are concerned about not just alzheimer 's but brain research in general because the brain has secrets up there that can benefit not just people with alzheimer 's but parkinsons and so many other diseases. so i hope people will begin to think that they have a voice and they can have impact with their vote.
>> that's good advice. you can go to today.com or nbc news.com and find out more information about the disease. thank you for shining a light on it.