In many ways, Gabby Gingras is a typical 7-year-old girl. She goes to gym class with other second-graders, loves playing board games, and idolizes her older sister Katie.
But at school she's always accompanied by a teacher's aide who monitors her every move. She wears a helmet and goggles every day. Gabby's life is dangerous in ways other kids cannot understand: She doesn't feel pain, and is at constant risk of badly injuring herself.
When Gabby was four, she participated in a documentary called "A Life Without Pain." In the video she banged her head into the sharp corner of a table, but she just kept on going. Later,a dog collided with her, but Gabby remained unfazed.
For the first four months of her life, Gabby was the perfect little baby. It wasn't until she started teething that her parents, Steve and Trish, noticed some odd behavior.
"I was massaging Gabby's gums one day, and she bit down on me ungodly hard. It was so hard, I couldn't stand it," Steve said. "When I pulled my finger out, I pulled a tooth out of her mouth — and she's just happy playing like nothing happened."
It was as if she didn't even feel it. And that was just the beginning. The four-month-old would teethe on anything — plastic toys, hardcover books, even her own fingers, until they were bloody.
"She had damaged them so badly it really looked like raw hamburger," Trish said. "It was that chewed up and mangled."
"She would also chew on her tongue like it was bubblegum," Steve said.
It was bizarre and frightening. Steve and Trish brought Gabby to doctor after doctor. For months, specialists tested the baby for everything, from metabolic diseases to rare genetic disorders — and ruled out one disease after another. At 7 months, the Gingrases were no closer to an answer.
Trish became so frustrated she spent an entire weekend searching the Internet for answers. Suddenly, she found some pictures of kids with fingers that looked like Gabby's.
"That was the first time we'd heard the term 'hereditary sensory autonomic neuropathy,'" Steve said.
HSAN is an extremely rare genetic disorder that affects the sensory nerves. In Gabby, the nerve fibers that detect pain and temperature never developed. There is no cure.
Dr. Felicia Axelrod, one of the foremost experts in the field, said the most profound abnormality is that Gabby cannot feel pain.
"She could break a leg, she could scratch her eye, and not even be aware of it," Axelrod said.
Her parents tried to give Gabby a normal childhood, but they also wanted to protect her.
"We put velcro braces on her to keep her arms straight so if she can't bend her arms, she can't put her fingers in her mouth and bite them," Steve said.
"I'm the worst playground mom, because I'm like, 'Oh, look, ah!' You know, I'm always the one standing under there: 'Don't! Don't climb that high, please!'"
The Gingrases, on their doctors' advice, had all of Gabby's baby teeth pulled, to keep her from injuring herself. But that caused her adult teeth to grow in early — and Gabby knocked out all but one of those.
"I'm thinking, here's my beautiful girl, she's not going to have any teeth, people are going to make fun — you know, everything that goes through your mind," Trish said.
They plan to give Gabby dentures when she's done growing.
But what terrifies Gabby's parents the most is the fear that she could make herself blind. Trish recalled the time Gabby turned 1 year old.
"She woke up from a nap, and I thought, 'Oh, there's a little bit of fuzz or fluff in her eye,'" Trish said. "It wasn't fuzz, there was a real mark on her cornea. So I quickly called the local doctor, and he said, 'If you had this, you would be in such excruciating pain you couldn't open your eye.'"
Gabby's left eye was so badly damaged that her doctor stitched her eyelid shut in a desperate bid to save her vision. But because Gabby didn't feel the pain of it, she ripped her own stitches out.
Then Steve came up with the idea of using swim goggles to protect Gabby's eyes. But it was already too late. She had lost the vision in her left eye. And now it was at risk of developing into a life-threatening infection.
The only solution was to remove the injured eye.
"It just brings back those images of the hospital, and letting her go on the gurney, and, and now it's — No parent should ever have to watch her child do that," Trish said.
"I remember it being an easy decision that we needed to take the eye out — but it was, we weren't fixing anything. It was taking something away."
Today Gabby has an artificial left eye. She wears a protective contact lens over the right one, which is also damaged. For good measure, she uses safety glasses during the day — and those swim goggles at night.
Despite these precautions, she still manages to hurt herself constantly. Gabby told "Primetime" that she had once broken her jaw without even knowing, because it didn't hurt.
Experts aren't sure whether kids like Gabby can reach adulthood or have normal lives.
But Joann Cruz might be a glimpse into Gabby's future. Cruz, 37, has also never felt pain. The damage she has accidentally done to her body is mind-boggling. But most impressive of all is her determination to live as normally as possible.
"My parents, especially my mom, always told me, 'There's nothing different about you. You're a regular person.' And I always believed that," Cruz said.
Cruz added she doesn't know what pain feels like. Millions of Americans suffer from back pain, but Joann has repeatedly damaged the discs in her spine and never known it. She's had six major back surgeries and a rod inserted to hold her vertebrae together.
"This last one that I had last year, I broke the rod. They had inserted a rod, and I broke it, and I didn't know I broke it," Cruz said. "The only reason I knew I broke it was because as I walked, I could hear it. You could hear it, crack, crack, crack. And I started slouch — slumping over. So if you were standing behind me, you could see the actual broken rod in my back — and my doctor said that only I could do something like that."
Joann's whole life has been filled with unimaginable injuries. The wounds began appearing when she was very young. When teething she bit herself, gouging her lip so badly the damage is still present.
Like Gabby, Joann also had all her baby teeth pulled — and later needed surgery to allow her adult teeth to grow in properly.
For Joann, even simple things can hold untold peril — like knowing when the water gets too hot. Even if it is scalding, she doesn't experience pain.
For years, Joann did not have a name for her condition. She always accepted it as being part of who she was as an individual. When she got married, it never even occurred to her to tell her husband Alex. He never knew about her condition until three years into their relationship, when she was giving birth.
"I don't think she knows this, but they cut her. When the baby was coming out," Alex said. "She was just laying there. And the doctor was even amazed."
Joann didn't know there was anyone else like her until two years ago when she finally met Gabby, someone who could understand.
"Oh, it was so nice," Joann said. "We hugged and kissed like if we knew each other for years — I saw myself in her."
It wasn't just a lack of pain that united Joann and Gabby, it was also the pain they did feel.
"The kids used to make fun of me," Joann said, "because I didn't have any teeth."
She responded to the teasing by playing the clown and making jokes.
The memories brought tears to her eyes.
"It used to bother me a lot," Joann said. "You know, because they used to make fun of me and call me names, and I always ignored it."
To help Gabby and others with HSAN, Joann scheduled a visit with Dr. Axelrod, the same doctor who treated Gabby. Axelrod said she has never met a patient as old as Joann.
First, she administered a simple test to see if Joann could feel pain when poked with a sharp pin.
"Her tongue is rather smooth," Dr. Axelrod said. "What she's missing are the bright red dots that should be on the tip of someone's tongue — and the taste buds that are missing are the taste buds for sweet."
Joann had no idea her sense of taste was altered, but it is quite common for people with HSAN. She also found out that she can't make tears in her right eye. Her left eye, however, is normal.
Then Dr. Axelrod put a tiny cotton thread right on Joann's eye, an action that would hurt most people. But Joann didn't feel a thing.
After all the testing was done, it became clear that Joann does indeed have HSAN. Even so, Joann says her life has many rewards, such as her two healthy children — Alexis, 11 and Jordan, 9.
Gabby's parents, Trish and Steve, have started a foundation called Gift of Pain, a support group for people with HSAN. So far they have found 39 people who think they have the condition.
"I don't want another mother to ever sit where Steve and I sat five or six years ago and say, 'What is going on? Why can't I get help? Why can't I get information?'" Trish said. "That's really what motivates me."