Triangle toddler among fewer than 100 people ever diagnosed with an ultra-rare genetic condition

RALEIGH, NC (WNCN) — A little girl in the Triangle is living with a genetic condition so rare that doctors around the world are still trying to learn more about it.

Thea Halsey has been through a lot in her three years, and her parents aren’t sure what life will ultimately look like for their daughter, but they say her smile and her spirit inspire everyone she meets.

When Thea Halsey giggles, it’s hard not to laugh along.

“It makes you want to smile. It warms your heart,” said her mom, Hayley Halsey, a smile spreading across her own face.

Halsey hopes it’s her daughter’s smile people see before they notice her feeding tube or hearing aids, before they realize she’s been through so many surgeries that it’s hard to keep track of them all.

“The first surgery she ever had was the day after she was born,” Halsey recalled.

She and her husband, Andrew, overjoyed at the birth of their first child, realized quickly that their journey would look a little different than they’d planned.

Although Halsey says some of Thea’s tests before birth showed a heightened chance of Down syndrome, other tests came back normal.

After Thea’s birth, the newborn was rushed to the NICU, and then to another hospital.

“It’s not the picture-perfect dream you had about bringing your child home,” Halsey noted.

Thea faced one medical issue after another — involving her heart, her hips, her hearing, and her digestive system, but her sweet spirit helped her parents to take it all in stride.

“She’s always been happy, and she’s always been a joy,” said Halsey.

The couple debated whether to do extensive genetic testing to try to find a diagnosis for their daughter.

“We went back and forth, me and Andrew did, about whether or not we wanted to do it, but we figured the more knowledge we had the better to hopefully help her with in the future,” Halsey explained. “I think it was either April or August of last year we got the diagnosis that it was the PHF6 gene mutation, which is associated with Börjeson-Forssman-Lehmann Syndrome.”

The condition, also known as BFL Syndrome or BFLS, is so unusual that Dr. Cynthia Powell, a pediatric geneticist at UNC Health and an expert in rare diseases, says only between 50 and 100 cases have ever been documented worldwide.

“There’s rare, there’s ultra-rare, and there’s nano-rare, and I think this one would almost fall into that nano-rare where it’s just extremely few numbers of people recognized with it,” said Powell. She noted, though, that some cases may have gone undiagnosed.

While doctors know the syndrome is caused by a mutation on the PHF6 gene, Powell says scientists are still working to determine exactly what that gene does.

“We think it has a role in what’s called ‘neuronal migration,’ cells in the brain getting to the right position as the embryo is developing into a baby, and so those cells don’t seem to get to the right locations always,” she explained. She said the gene may also play a role in how DNA becomes RNA.

Until recently, Powell says, it was believed that BFLS only affected boys.

“It’s really only been in the last 6 or 8 years that we found that it can also occur in females,” she said.

While she noted that the gene mutation that causes this disorder can be inherited, it can also occur spontaneously, which seems to be the case with Thea.

“Our genes change, our DNA changes for reasons we don’t completely understand,” Powell noted.

There is no treatment for BFLS, which is associated with developmental delays. Thea receives numerous types of therapy, but because the disorder is so rare, the Halseys aren’t really sure what to expect.

“I don’t think anybody has ruled out that she will speak or walk or anything like that,” said Halsey. “We’re kind of all just on her timeline and we are pushing for those things, but if they happen not to get there then that’s the path we’ll go.”

They also don’t know whether her medical issues — like a heart defect that recently required surgery — are a result of the genetic condition or unrelated.

“She has some problems that we haven’t found before in other patients,” noted Powell, adding that doctors still have a lot to learn about the condition, and every patient diagnosed can provide valuable knowledge.

“The more we learn,” said Powell. “The more we can help other families in the future.”

As Thea grows up, her experience may one day teach doctors more about BFL Syndrome, but at 3, she’s already teaching everyone she meets other important lessons.

“They see she has some of those delays, but that doesn’t make Thea,” said Halsey. “Thea’s personality outshines all of that.”

Her journey may be more difficult than her parents ever expected, but it’s a journey, Thea fills with joy.

“We wouldn’t change her for the world,” said Halsey. “And we would go through it all again just to have her again.”