Jennifer Portnoy loves her son Javier Romero, a four-year-old boy she may very well outlive.

Before Javier was born, Portnoy said she was full of hope. “Just like anyone pregnant for the first time,” she said. She imagined where he would go to school — “He’d go to Harvard or something,” she said — and to whom he would get married. Later in life, he would become an actor. It made sense, “with the name Javier,” she explained.

Portnoy doesn’t have those dreams anymore. If she does think of things like that, like being a grandmother, it’s only in the context of Javier’s fatal illness.

At the age of one, Javier was diagnosed with Duchenne muscular dystrophy, a rare genetic disease characterized by rapid muscle degeneration.

Those with the disease usually die in their teens or early 20s because of heart and respiratory complications, according to the Centers for Disease Control and Prevention. By then, most children are already confined to wheelchairs, unable to walk because of their deteriorated muscles.

When Javier was diagnosed, Portnoy was devastated, and her husband, Rich Romero, was in denial. But as she moped around, she realized that her behavior would not help her son.

With the help of her family, Portnoy rebounded and now devotes countless hours to researching Duchenne and assisting her son. It’s stressful, she said, but she has to stay busy.

Portnoy, 36, is determined to defy the odds. She’s trying to keep her son alive and as healthy as possible in a country where Duchenne affects a tiny portion of the population — about 20,000 newborns each year, according to Parent Project Muscular Dystrophy, an organization focused on Duchenne. That’s about 0.4 percent of the total births in the United States.

The disease is rare, yet it is the most common fatal genetic disorder among children. To date, Duchenne has no cure.

“It was like being given a death sentence for your child,” Portnoy murmured, referring to Javier’s diagnosis. He was talking with his father in the other room. “You want it to happen to yourself, you know. You wanna fix everything, but this is unfixable.”

It took a year for doctors to find out why Javier’s blood looked abnormal, and when they did, Portnoy said she tumbled into depression. She described nights when she would lie in bed, in the dark, and cry.

“I couldn’t get out of bed. I felt completely drained,” she said. “I just stopped hoping.”

Javier’s shortcomings were obvious, Portnoy said. “I’d pick him up from school, before he even knows I’m there, and watch him play with his friends,” she said. “He can’t jump, yet it’s something so simple.”

Javier used to attend physical therapy at St. James hospital, but it was difficult for Portnoy. “A lot of the kids there would get better and not need it anymore,” she said. “But I knew he was not getting any better.”

Now Javier does physical therapy at his preschool because it’s more convenient.

Portnoy’s family could see she was in pain the first year, and they intervened.

“We could constantly be there for her,” said Anastasia Pornoy, her sister. Anastasia said the family told Portnoy over and over, “You’re not doing it alone. You’re not gonna go to pieces, and Javier needs you.”

Since then, Portnoy has done, and is doing, a lot to help her son. “I realized while I’m crying about this, he’s still alive,” she said.

Shortly after, Portnoy formed Hope for Javier to “fund the science that will save Javier’s life,” she said. The proceeds will go to research that will help find treatments for Javier.

She spends at least six hours every day working on the charity, maintaining the website, replying to donors personally, researching new treatment breakthroughs and contacting other families with children with Duchenne.

Getting Javier into a clinical trial is Portnoy’s ultimate goal. The trials would give researchers the opportunity to collect data for new drugs that could help slow Javier’s disease. Javier has a special mutation of Duchenne, however, so his current clinical trial options shrink to zero. Portnoy, however, is hopeful.

“If I don’t get Javier into a clinical trial, that’s the end of it,” she said. “We want to invest in things to buy him more time.”

Every day Portnoy and her husband give Javier his daily medicine doses and stretch him. He already wears leg braces to keep his heel chord stretched, but wakes up at night because of leg pains. He can’t sit up entirely by himself, either.

Still, they try to carry him out to do things that “normal” children do. During the summer they went to the beach almost every day, and they go to the city often to play in Central Park.

“I’m really just trying to enjoy each day that I have with him than mourning the days I won’t.”

“There are people like Jen who get the diagnosis and say, ‘I’m a fighter,'” said Pat Furlong, president and CEO of Parent Project Muscular Dystrophy, who lost two children to the disease. “We don’t have a choice, we can’t give up.”

Portnoy occupies herself constantly with charity and research duties that sometimes takes away from her time with Javier, but when that happens, Rich is there for him.

“She’s really running this circus, so my job is to help this along,” Rich said. “She’s so busy sometimes that he needs someone to hang out with.”

“It stresses me out a lot, but I have to be busy,” Portnoy said. “I take on more than I can do, but I’ve learned to ask for help.”

Portnoy’s sister helps out with the charity, and they don’t hire any assistants to make sure all donations go straight to charity. They’ve collected about $250,000.

“I need to be able to look him into the eye at the end of the day and say I did everything I could,” Portnoy said.

The only regret she said she had was criticizing Javier before his diagnosis. “I was like, ‘Hurry up. Come on. Get up the stairs already,'” she said. “I was always frustrated like, ‘Why can’t he just do this?’ But I have no other regrets.

“If you regret something it means you could have done something differently,” she continued. “Maybe regrets will come later.”

“She’s a lovely mom,” Furlong said. “She’s the type of person where a child can lay in her lap and feel loved.”

As far as Javier’s knowledge of his own disease goes, he only knows that he has “special muscles,” Portnoy said.

“We have a policy of honesty. I wouldn’t keep anything from him.” But at the same time, the couple hasn’t sat Javier down and told him. “One day I will have to tell him.”

“I just look at him, even when he’s being a wicked toddler,” she said. “But this is it. This is today.”