Chantilly High Assistant Principal KT Lynch doesn’t have Chiari Malformation, but one of her sisters and a niece do. So next week, Lynch, of Fair Lakes, will participate in a fund-raising walk to raise money to help them and others.

The Conquer Chiari Walk Across America will be held Saturday, Sept. 26, at 8:30 a.m. at Ida Lee Recreation Center in Leesburg. It’s at 60 Ida Lee Drive, N.W., off Route 15. The course is just one mile, and this walk is one of 30 being held simultaneously across the nation for this disorder.

"We’re hoping for a big turnout because I know how it’s affected my family," said Lynch. "And if we can raise any money for research, it can help those who have it and lessen the heartache, trials and trauma for others who may be unaware they have it."

Chiari Malformation is a neurological condition in which the bottom part of the brain, the cerebellum, descends out of the skull and crowds the spinal cord, putting pressure on both the brain and spine. The results are problems including debilitating headaches, neck pain, weakness and numbness in the limbs, balance problems and visual disturbances.

It affects more than 300,000 people in the U.S. and one in 1,000 people nationwide have it. Still, said Lynch’s sister, Teresa Wheeler of Leesburg, "Most people have never heard of it. It can happen from trauma or injury, but it can also be congenital — and that’s why research money is so important to help find out these things, raise awareness and get people involved."

ANOTHER SISTER, Patti Sinnen of Waterford, believes hers happened in a bus accident when she was 30. She sprained her lumbar region and has suffered with severe migraine headaches and a sensitivity to light, sound, and touch, ever since.

"The only way to tell you have it is by an MRI," said Wheeler. "There are still doctors who don’t know about it." Added Sinnen: "They still don’t know if it’s hereditary."

Wheeler hasn’t been diagnosed with it, but her daughter Grace, 9, has. "This piece of brain hangs down, like an internal tail down the back of your neck," said Wheeler. "And anytime you bend or move your head, it causes pain and can block the flow of spinal-cord fluid to the brain."

When Grace was a toddler, said her mom, "When she’d get her hair cut, she’d freak out bending back at the shampoo bowl because of the pressure it placed on her brain. It caused her a lot of pain."

"But I couldn’t really explain," said Grace. "I would just scream and yell." Finally, when she was 6 and having double vision, a pediatric ophthalmologist discovered her problem.

Her symptoms continued worsening and, in May, she was operated on successfully. Her Chiari no longer presses against her spine or skull. Said Sinnen: "It has more space now so the pressure is relieved."

However, said Wheeler, "Only children can have this surgery; it can’t be done on adults." So Sinnen still suffers.

"Even atmospheric changes in pressure affect her," said Lynch. "So whenever a weather front is coming, I call Patti to see if she’s OK. Your skull protects your brain from these changes; but with the brain tail hanging out, it’s like a lightning rod."

THAT’S WHY they’re hoping to raise at least $12,500 from the walk. "For years, we’ve done an Alzheimer’s walk because our mom has it," said Lynch. "But when we learned there was no walk for Chiari in the Washington Metropolitan area, Teresa and Patti organized this first one, along with Patti’s daughter Kelly, who’s 24."

The proceeds go to Conquer Chiari, the national nonprofit organization working on research and awareness. "To participate, they’re asking for $25 donations, but people may give whatever they want," said Wheeler. To register for the walk, or make a tax-deductible donation, go to www.conquerchiari.org/index.htm. Registration may also be done in person that day.

There’ll be music and refreshments, and two Washington Redskins cheerleaders will also be at the walk. Raffled off will be a Redskins mini-helmet donated by running back Clinton Portis.

"We’ll also have door prizes," said Sinnen. "Any business wanting to donate anything may contact us at chiarimom@ymail.com."

"There’s also a variety of kids’ activities," added Lynch. "Since I used to be an art teacher, I’m going to do face painting. I’ll also be walking with my family, and Chantilly National Honor Society members can receive service hours for working at this event."

Two years ago, Lynch had a student at Chantilly with Chiari. But already knowing about this disorder helped her work with that student’s family and teachers to develop "good educational strategies" for the student.

Now, she hopes lots of people with Chiari will be helped by Virginia’s first, fund-raising walk for it. As for the three sisters, said Lynch, "This is what our family does — we all pull together."