The phone call she least expected on her birthday last November became the one Denise Schneider would treasure the most.

It came from Caleb Bupp, MD, FACMG, a Spectrum Health medical geneticist. Denise and her husband, Tom, had met with Dr. Bupp four months earlier to introduce him to their daughter, Haylie, then 17.

After learning about Haylie’s complex medical history, Dr. Bupp helped the Stanton, Michigan, family pursue genetic testing.

They had blood samples drawn, then went into waiting mode, knowing genetic analysis can be a slow process.

Now Dr. Bupp had the lab’s results in hand. With those results, he was about to provide something that had eluded doctors all of Haylie’s life: an explanation for her unique combination of physical characteristics, developmental disabilities and seizures.

Answers her parents had sought for 18 years.

“I’ll never forget the conversation,” Denise said.

“Dr. Bupp said, ‘Denise, I want you to know we have a diagnosis for your daughter.’”

The tests revealed Haylie has an extremely rare genetic mutation. It’s not something Denise and Tom passed on to her, Dr. Bupp assured her. Nor is it something their older daughter, Brooke, is at risk of passing on to her children.

Remembering the relief she felt that day still brings tears to Denise’s eyes.

“To have that diagnosis was just unbelievable—to know that nothing that we had done had caused this, that this was a complete fluke,” she said.

“We have always, always questioned if this is something that we did.… As a mom, I have beaten myself up for 18 years wondering, ‘What did I do wrong? What activity may I have done while I was pregnant? … What could I have done to prevent this?’”

Now she and Tom knew, definitively, that nothing they’d done had caused Haylie’s medical and developmental issues.

And best of all, they didn’t have to worry about their grandchildren.

“That was, to me, the biggest relief,” Tom said.

Not that Haylie hasn’t been a huge blessing to their family—both Tom and Denise underscore how much she has enriched their lives.

But they’re also candid about the sorrow they’ve experienced over the years, knowing their daughter couldn’t experience life like other children, and about the stress that comes with raising a child who needs 24/7 care.

“She’s taught us a lot and brought us closer,” Tom said. “(But) it was a struggle.”

No answers

Denise and Tom learned something was amiss just moments after Haylie’s birth in September 2000.

“The doctor, as soon as he got his hands on her, said to us, ‘Does dwarfism run in your family?’” Denise said.

Shock marked her response: “Excuse me? What are you talking about?”

Her pregnancy had been normal, with no hint of trouble.

Yet, Haylie arrived with several physical differences, including disproportionate limbs, back-set ears and abnormalities of her fingers and toes.

From the start, doctors told Denise and Tom that Haylie likely had a form of dwarfism, which wouldn’t affect her cognitively.

But within weeks the couple knew Haylie’s differences were more than physical. She didn’t interact with them the way an infant should.

“No connection,” Denise said. “She wasn’t looking at us, she wasn’t responding like a typical baby. No smiles whatsoever.”

The couple grew increasingly concerned.

At two months, their pediatrician said not to worry, just give it time. At four months, his advice remained the same—even when they pointed out that Haylie, at 10 weeks, had started making jerking movements that resembled small spasms.

A week later, the Schneiders met a retired pediatrician who was filling in for Haylie’s regular doctor. He took their concerns seriously, recognized that their baby had deeper problems and referred them to a pediatric neurologist and a geneticist in Lansing.

The specialists ordered a series of tests—CT scan, MRI, EEG, X-rays—all in an attempt to determine what disorder little Haylie might have.

The tests revealed that, though her brain showed no structural abnormalities, she experienced constant seizure activity. Hence her spasms.

This discovery started Haylie on a lifelong journey with antiepileptic medications, in various combinations and dosages. None of them proved successful at controlling her seizures.

At the same time, neither doctor could come up with a diagnosis that fit Haylie’s situation.

“They were just baffled with everything,” Denise said.

The search for answers continued: When Haylie was 2, her geneticist sent a new set of X-rays to the international registry of dwarfism, hoping to match her with a specific disorder.

The result—a distressing misdiagnosis suggesting Haylie wouldn’t live to see her third birthday—left the Schneiders disillusioned with genetics.

It took seven years for them to consider trying a new type of genetic testing, but again the results came back inconclusive.

‘The Haylie syndrome’

Left without a diagnosis for Haylie, the couple simply moved forward, accepting the unknowns and settling into a rhythm.

They built a home on wooded land near Denise’s parents’ house, pursued their careers and enrolled Haylie and her older sister in school. Haylie’s program specializes in teaching kids with developmental disabilities.

“We kind of just went on with life,” Denise said.

For insurance purposes, doctors labeled Haylie’s disease as cerebral palsy and epilepsy. But the family gave it their own name.

“We just said, ‘She’s unique and she has the Haylie syndrome,’” Tom said.

Though Haylie is nonverbal, she knows how to communicate with her family and teachers. They know when she’s hungry, when she’s happy, when she’s not feeling well. They know she adores music, lights, bath time and snuggling.

And though she needs to be fed and diapered and carried, Haylie goes everywhere the family goes.

“I haven’t taken her downriver yet in a canoe—that’s one thing I’d like to do,” Tom said. “But I’ve taken her hunting with me. … I want to treat her the same as I would any kid.”

A couple years ago, Haylie served as maid of honor in her sister’s wedding.

“Growing up, Brooke embraced everything about her sister,” Denise said, and Haylie attended nearly all of Brooke’s basketball games.

The sisters remain each other’s biggest fans.

A diagnosis

As Haylie slowly grew, complications arose. She developed scoliosis and chronic respiratory issues and began seeing specialists at Spectrum Health Helen DeVos Children’s Hospital. There she had her tonsils and adenoids removed at age 10 and underwent scoliosis surgery at age 11.

Haylie remained under the care of her initial pediatric neurologist until last year, when he referred her to Angel Hernandez, MD, division chief of neurosciences at Helen DeVos Children’s Hospital, for a second opinion.

Dr. Hernandez asked whether she’d ever participated in genetic testing. The couple told him about their negative experiences with genetics. Though he understood, he felt confident in the hospital’s genetic services for children and encouraged them to meet with Dr. Bupp.

They agreed.

“When we met with Dr. Bupp, he won us over. He was fantastic,” Denise said.

Science had made great strides in the years since Haylie last had genetic testing, Dr. Bupp explained. Now they could have real hope of learning the key to her disease. And their insurance would help cover the cost.

The Schneiders took the leap, signing off on a genetic test called whole exome sequencing.

“It’s done with a little bit of blood, typically, and it looks at our entire genetic code and looks for any misspellings or mutations in it,” Dr. Bupp said.

That analysis, completed last fall, revealed a diagnosis.

“It found a genetic difference in her that was not something that either of her parents had,” Dr. Bupp said. “So we’re able to say it’s a new genetic change in her. And it causes a specific condition that was a pretty good fit for her symptoms.”

The mutation, in a gene called SLC35A2, causes a problem called a congenital disorder of glycosylation. Though this type of disorder can have various causes, Haylie’s specific genetic change matches her rare combination of physical features, developmental delays and intractable seizures.

A new chapter

Shortly after Denise’s unforgettable phone call from Dr. Bupp, she and Tom met with him to learn more about the SLC35A2 mutation.

In Haylie’s case, having an answer doesn’t bring a cure, the doctor said, but it brings peace of mind and opens up opportunities to help other families.

“You’re looking at her in a new light, in a way that changes everything,” he said.

That message rang true for the Schneiders.

Learning that seizures are an inescapable part of Haylie’s disease brought them peace by confirming their decision, years ago, to limit her antiseizure drug dosages, Denise said.

“That was another relief—to know that we’ve made the right choice for her, that she’s got quality of life because she’s not overly drugged up on medications,” she said. “(Now we know) that had we increased them, the seizures never would have stopped—it’s just a part of this diagnosis.”

In addition, the idea of using their experiences to help other families has long appealed to Tom and Denise.

“They say there’s 20 or less people in the world that have this, and Haylie is the oldest,” Tom said.

“So these families are in the same boat that we were. They now know what the diagnosis is, but they don’t know what to look forward to in the future with their kid. I would love to talk to them and help them so they can understand what we’ve had to do to help Haylie.”

The desire to support other families is something he sees repeatedly in his work with patients with rare diseases, Dr. Bupp said.

“What I usually tell families is … once we get a diagnosis and we talk about it, they know more about it than 99 percent of the world,” he said. “What happens to these families over time is they truly do become the experts.”

Families around the world often make connections on social media that help them feel less alone with their rare diagnosis, he said.

Besides exploring that route, Denise plans to return to a memoir she began writing six years ago about life with Haylie.

“I think this is God’s way of kicking me in the pants and saying, ‘You need to get busy,’” she said. “‘This needs to get out there. You need to touch families. You need to tell your story and help others.’”