Saving Carter: Family of boy with rare disorder dubbed 'childhood Alzheimer's' launches campaign to save him

The parents of a 6-year-old boy who suffers from a debilitating disorder likened to "childhood Alzheimer's" have started a campaign to save their son.

"Carter is probably one of the most loving children you'll ever meet," Jennifer Sarkar, Carter's mom, told "Good Morning America." "He's very affectionate, he's very playful. He keeps us on our toes and makes us laugh daily. He's sporty and outgoing and just loves to meet everyone."

In 2016, Carter Sarkar was diagnosed with Sanfilippo Syndrome, a rare neuro-degenerative disorder will take his ability to talk, swallow and walk. It's likely Carter will develop seizures and suffer severe dementia.

There is no cure, and Carter's life expectancy is his mid-to-late teenage years.

Now, Carter's parents are urgently trying to raise $1 million in one month to fund a clinical trial that could not only save Carter's life, but many others in a similar situation.

Sarkar said her son has begun to stumble when he walks, has lost some language skills and is experiencing very early stages of memory loss.

"I think what's been most eye-opening to us is, we'll be at our favorite place and he will be so scared and frightened," she said. "He's crying because he doesn't know how we got there. He starts to cry, I start to cry."

Sarkar said that Carter was diagnosed after she brought him to the doctor for unrelated chronic pancreatitis. Because Carter was not yet potty trained, the gastroenterologist suggested she bring him to a geneticist.

"After 30 seconds [the geneticist] looked at him and said, 'He might have Sanfilippo syndrome,'" Sarkar said, adding that children with the disorder have similar facial features.

Sarkar said she inquired about treatment options, but doctors told her there wasn't a cure.

"[The doctor] said, 'You just have to go home and love on him," Sarkar recalled. "No parent should ever have to bury their child. My husband and I went into a dark place. It wasn't just about the pain and suffering that was going to happen to him, it was about our daughter and how this was going to affect her as well."

In 2017, ABC News covered Carter's story when his neighborhood held a Halloween block party for him five months early.

At the time, Cara O'Neill, a pediatrician and the scientific director at Cure Sanfilippo Foundation, had said Sanfilippo syndrome is caused by children not having enough of an enzyme to break down normal byproducts of cell metabolism.

"It builds up and causes damages to the cells, but particularly brain cells," O'Neill explained.

Divya Vats, Carter's doctor, told "GMA" that Sanfilipo affects about 1 in 70,000 children.

"Unfortunately, because there is no proven treatment and the disease always gets worse, patients with this disease usually don't live past their teenage or early adult years," said Vats, a physician and biochemical geneticist at Kaiser Permanente in Southern California.

"The metabolic genetics team at Kaiser Permanente is committed to assisting and guiding patients with these kinds of disorders to suitable clinical trials and treatments," he added. "Given Carter’s situation, he is doing remarkably well right now. His parents are doing a great job caring and advocating for him."

There are four types of Sanfillippo. Carter has Sanfillippo type A, which Sarkar said is the most common and the most severe.

For now, Carter's family keeps his brain active with speech therapy, physical and occupational therapy, music therapy and more.

"He's progressing, which is great, especially when doctors say they lose their speech and language around 5 with this disease," Sarkar said. "We are consistently trying to keep him on his toes so we have a little more time with him."

On May 22, Jennifer and Samir Sarkar created the crowdfunding page savingcarter.com, which has generated more than $400,000 and will close on June 22. Their goal remains $1 million.

All funds will go to the nonprofit Cure Sanfilippo Foundation, which is funding the trial that could give Carter a second chance.

"The research is a novel enzyme replacement therapy that has had remarkable results of helping fix the brain in closely related diseases," Sarkar explains on the website. "We are currently racing against time to fund this trial and get it up and running. It will help Carter and so many other kids also hoping for a chance at life."

Glenn O'Neill, president of Cure SFF, said that the Sarkars have been raising awareness and funding for research for not only Carter, but for thousands who suffer from this disease.

O'Neill explained that the only chance for these kids to survive is they must meet certain criteria to be included in a clinical trial.

A common reason why children with Sanfilippo syndrome are left out of trials is because there's a very limited number of trials and spots, O'Neill added. Currently, there is one trial one for type A of the disorder and one trial for type B. Both only have a handful of spots remaining, with Phase 1 trials only including six to 20 patients.

"Children left out of clinical trials, regardless of the reasons why, have no chance at life, unfortunately," he told "GMA" in a statement. "Saving Carter is a story of one family and one child. It is an urgent push to help raise $1 million to fund this novel enzyme replacement therapy and bring it to patients who desperately need it, like Carter."

"We know what the next five years are going to look like," Sarkar said of her son, "so we are trying to do everything we possibly can to change that for him."