At age 4, Nathan Milto was a typical preschooler: he enjoyed singing songs, playing on the computer and practicing hockey slap shots with his Dad in the basement of their Indianapolis home.
But in a just a few months, a rare neurodegenerative disorder known as Late Infantile Batten disease would transform Nathan's happy childhood into a living nightmare.
By his fifth birthday, the disorder had caused Nathan to lose his eyesight, and at age 6 he was put on a feeding tube.
"We had absolutely no idea this would happen," said Tricia Milto, Nathan's mother. "He was a perfect baby – Nathan actually hit all his milestones three to six months ahead of where he should be – until he turned four."
As Nathan approached his seventh birthday in 2001, he had lost his ability to walk and talk and was bedridden, unable to communicate except by way of facial expressions and an occasional hand gesture.
Meanwhile, Tricia and her husband Phil Milto had been noticing similar problems with Nathan's younger brother, P.J., who at just three and a half years old was also having trouble seeing and communicating.
Like his brother, P.J. became one of only approximately 500 children worldwide diagnosed with Batten disease. P.J.'s condition progressed so quickly that just two years later the six-year-old was uncommunicative and confined to his bed.
According to Dr. David Pearce, an associate professor at the Center for Neural Development and Disease at the University of Rochester Medical Center who has been researching Batten disease for more then 10 years, the cruelest part of the inherited disorder is the delay of noticeable symptoms.
"You'll have a child who is a fully formed five-year-old and then you will gradually take all of their functions away – starting with their vision and then their brain eventually deteriorates," said Pearce.
"The body tries its best to compensate for the [defective gene] but it reaches a threshold [around age five] where it just can't cope anymore," said Pearce. "That results in a system breakdown."
But standing idly by to watch his two sons slowly die was not an option for Phil Milto, who has now spent more than 10 years trying to find a treatment for children with Batten disease.
Milto established Nathan's Battle Foundation, a non-profit biotech firm that raised millions to fund gene therapy trials at the Medical College of Cornell University, which has since developed a drug that has proven to slow the progression of the disorder.
A lack of funding for additional clinical trials for the drug – which in its first form succeeded in slowing the progression of the disorder – has halted its development.
Like Milto, Lance Johnson, the executive director of the Batten Disease Support and Research Association, said losing his daughter to the disease spurred him into action.
"When you get diagnoses like Batten disease all your hopes and dreams are shattered – they disappear into vapor," said Johnson, whose daughter Lorena died at age 22 in 1993.
Johnson said that Lorena began having vision problems at age six and developed seizures at age nine.
She went blind at age 13, was unable to walk at 15, lost her speech at 17 and by her 19th birthday was incontinent and hooked up to a feeding tube. At age 20, Lorena had lost her movement in her hands and fingers. She died two years later.