Eight-year-old Quinn Hoover, who lives in suburban Omaha, Nebraska, was born with hypophosphatasia (HPP), a rare genetic disorder that affects the development of bones and teeth. The symptoms can be frightening and perplexing. Kara Schweiss, Quinn's mom, shared the family's story with TODAY.
I was 40 when I became pregnant with him, so I was watched very closely. Nothing indicated any problems. When Quinn was born, he weighed almost 11 pounds — he was this big, vigorous baby. So I didn’t have any reason to suspect anything was wrong.
At his first well baby check-up, the pediatrician noticed his head circumference had increased significantly more than it should have. He also had plagiocephaly, which is asymmetrical skull.
There were other symptoms. When you hold a newborn baby in front of you and touch the baby’s feet to the ground, they usually stiffen their legs. He never did that. He couldn’t stand on his own until he was a year-and-a-half old. We knew he was delayed, we didn’t know why.
He would have fevers during sleep. His feet were flat to the point where they were almost convex. He had low muscle tone and speech articulation problems. It was just all these strange things.
At 13 months, one of his newly-formed baby teeth fell out. I thought, “He must have hit his mouth, he had some sort of accident,” but the doctor found no evidence anything happened.
Then a couple of months later, he lost three more. By the time he was 3, he had lost all six bottom teeth. We knew something really wasn’t right. A pediatric dentist suggested he might have a metabolic disorder.
A blood test showed Quinn’s alkaline phosphatase (ALP) levels were about 10 percent of what they should have been. Genetic testing confirmed he had hypophosphatasia. I think our first reaction was, “What the hell is that?” It’s not a medical condition that gets a lot of attention. The disorder impacts about one in 100,000 babies, according to the National Institutes of Health.
We have another son and he doesn’t have hypophosphatasia. Less than 1 percent of people are HPP gene carriers, so the odds of me being a carrier, my husband being a carrier, us having two different mutations and our son inheriting both our mutations are pretty significant. I wish it would apply to when we buy lottery tickets.
It was eye opening to learn about how all of these seemingly unconnected symptoms we were observing actually had a common cause.
The metabolic process takes a lot of effort because my son doesn’t have sufficient quantity or quality of the alkaline phosphatase enzyme, which is necessary to metabolize mineral substances into bone and tooth tissue. His body has to work a lot harder to create bone and teeth, so he has “soft bones” — they’re not as firm and strong as they should be. As he gets older and heavier, there’s a greater burden on his skeleton.
When his gait trainer and wheelchair were delivered on the same day in 2015, I felt like hypophosphatasia had defeated him: it made such a significant impact on his life that he now needed mobility support.
I was having a hard time just keeping it together until Quinn took one look at the gait trainer, stepped into it and zoomed up and down the driveway. He was thrilled. That really changed my outlook.
He just takes everything in stride and he’s never had a “pity me” moment. I mean, he’s tried to use hypophosphatasia against me a couple of times, like when I tell him to clean his room and he says, “But mom, I have soft bones.”
He is at a higher risk for fracture. If most kids jumped from the bed to the floor, it would probably be no big deal. But that’s something he’s not allowed to do. Miraculously, he’s never had a fracture.
I’m trying to make sure he gets to do all the things other kids get to do with reasonable accommodations. He was eligible for a wheelchair sports camp, even though he doesn’t rely on a wheelchair full-time. He tried modified sports — football, curling, tennis, soft ball, archery — and had so much fun.
He’s the first U.S. patient to receive insurance approval for Strensiq, the only available treatment for HPP. He gets six shots a week, which give his body the alkaline phosphatase it can’t produce on its own. That’s made a huge difference, but it's not a cure.
We don’t know what will happen during the fast growth periods that precede adolescence. It’s all kind of a mystery. The future is really unknown.
For more information and to connect with other families living with HPP, visit the Soft Bones Foundation.