“There have been some setbacks,” theOn Assignment with Richard Engelstar tells PEOPLE in an exclusive chat about the couple’s older child, who turns 4 this month and wasdiagnosed in 2017 with the raregenetic neurological disorder that leads to severe physical and cognitive impairments and has no cure, as of yet.

“He is starting to have seizures now, which is unfortunate,” Engel continues of Henry. “We put him on a seizure med. He has a compulsive repetitive motion that is becoming more pronounced … [putting] his hands in his mouth or [scratching] his eyes vigorously.”

“That’s somethingwhere we have to watch him constantlyto stop him from doing that because he could hurt himself,” he adds. “We started using these arm braces that have a splint in them to discourage him from doing that.”

Engel also reveals that Henry “has hip problems,” explaining, “Because he’s not walking and running around and jumping like normal kids, his hips aren’t forming like they should be. There’s a possibility we’re going to have to do major surgery on his hips.”

Courtesy Richard Engel

Richard Engel

Richard Engel

Engel — who welcomed his second child with Mary, sonTheodore “Theo,”four weeks ago — tells PEOPLE that Henry is “lacking a conductor gene” and that a medical team atTexas Children’s Hospitalis “trying to build a treatment that could help immensely.”

“It’s not that [Henry] has brain damage — although the seizures aren’t helping — but he’s lacking the protein so the brain isn’t functioning,” he says. “In Texas, they’re trying to fool the body chemically into producing more of the protein [safely]. If they can, then the other problems become less.”

Engel explains that Henry “has half the protein he needs,” and would “be dead” if that number was zero. But the team at Texas Children’sis “encouraged that they’re going tofind” an effective treatment for the little boy.

“If [they] can boost [the protein] to 60 percent, 90 percent, then it could really help,” says Engel. “There’s no reason to believe he can’t wake up — that he can’t learnhowto control his brain and his body. It would almost be like he was born from the moment the treatment began. We’re hoping, in a few years, we can start a treatment that is still being invented.”

Richard Engel and family.Courtesy Richard Engel

Richard Engel

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Engel praises his wife for“working hard” with “redoubling her effortsin physical therapy” for Henry, calling her a “tough woman” and sharing that she “puts him in a standing frame, in order to put weight on his hips. She holds him upright, an hour a day … exercising him, stretching him. More therapies than ever.”

“The problem is, while we wait [for a treatment], things deteriorate,” he adds. “The body starts to go, the hips start to go … the spine hasn’t been an issue, but it could be. We’re in a race against the clock no matter how much physical therapy we do, and we do a ton.”

But there isa “beautiful aspect” to the family’s experience, too, despite the challenges: “If we can do this, there’s a possibility of an enormous knock on effect. Because most of these genetic disorders behave in this same way.”

For more information on Rett Syndrome or to support the research being done with Henry, visitNRI.TexasChildrens.org.

On Assignment with Richard Engelairs Sunday at 9 p.m. ET on MSNBC.

source: people.com