Maxwell Freed is a 4-year-old boy that loves spending time with his twin sister, Riley.

"He's the sweetest, kindest, loving little boy. He's the son that every father would want," said Maxwell's father, Mark Freed.

But Maxwell has a neurological disease that's so rare it doesn't hasn't even have a name.

"They said SLC6A1, and I was like, 'No that sounds like a flight number,'" said Maxwell's mom, Amber.

SLC6A1 is a genetic disorder that can impact speech and movement. There has only been one study on the disease worldwide because it is so rare.

Doctors believe that the condition causes seizures, which worsen when the child turns 4. With so little information, there is no average life expectancy. But symptoms can become so severe that Maxwell could lose everything that makes him who he is.

"He would be alive, but not living," Amber Freed said. "It's actually the worst-case scenario, and you would need full-time care. And what do we do about twin sister?"

Maxwell's mom has since quit her job to give her full attention to finding treatment for her son. After 300 phone calls to researchers across the country, Dr. Steven Gray at the University of Texas Southwestern agreed to help.

Gray has a plan for a clinical trial that could potentially cure Maxwell and other children like him.

"What we're doing is taking the DNA those patients are missing, packaging it into a harmless virus, and then using that virus as a kind of molecular delivery truck to carry those genes back into their body, fix their DNA, and then hopefully treat their disease," Gray said.

Because the disease is so rare, government funding is out of reach, leaving the Freed family to raise $4 million on their own to make the clinical trial happen. The deadline to get the money was Friday, and they are still short hundreds of thousands of dollars.

"If we don't have the funding, we will lose our cue, and the whole project could be pushed back a year or two years," Amber Freed said.

That's time that Amber Freed says her son doesn't have. Maxwell is at the age research has shown symptoms may start to take a turn for the worst.

The Freed family is collecting donations on GoFundMe and on this website.

Amber Freed says the family is thankful for anyone who can donate, no matter the amount.