TODAY | May 09, 2013
>>> update on a medical mystery we first told you about last month. a young boy in north carolina who kept suffering strokes and doctors couldn't figure out why. well, now a remarkable discovery thanks in part to his appearance here on "today." nbc gabe gutierrez has the details.
>> reporter: when we first met 4-year-old kalin , his infectious laugh and love of fire trucks .
>> there's nothing about him that has the word quit in it.
>> his parents felt helpless, neither they nor his doctors near raleigh, north carolina , had any idea why kalin had suffered six major strokes leaving him blind in his left eye and weakened on his right side. but when his story first aired on "today" last month, a scientist at the national institutes of health in maryland saw it online.
>> and i was like, wow, what is this about?
>> reporter: turns out, doctors here had been studying four other children with multiple strokes and high fevers at an early age much like kalin .
>> you could pretty much stack their mri images one on top of another and see the exact same findings.
>> so, kalin , come on in.
>> reporter: so kalin and his family were brought in for testing and the doctors' suspicions are confirmed. he has an extremely rare genetic protein deficiency in his blood.
>> we found the levels are extremely low or even close to undetectable.
>> reporter: quite a discovery. the condition doesn't even have a name. these doctors might call it feof fever and early onset stroke. they're not quite sure how to treat it yet. although injecting fresh plasma is a possibility. if the fda approves. that could happen in several months.
>> it's a step in the right direction.
>> reporter: more than that, his parents say, it is the hope they've been waiting for.
>> we should give him a full, long life.
>> reporter: they are helpless no more as a medical mystery is one step closer to being solved. for "today," nbc news.