Skip links
X-linked hypophosphatemia (XLH)


“Let’s not look at what they can’t do. Let’s look at what they can do and what they’re going to do.”

Creeks full of cattails weave through green hills. Red silos stand tall over Wisconsin cornfields. Amid the countless acres of corn, an old peach orchard grows near a colorfully blossoming garden. From the garden, Erin՚s voice rings with the delight of a mom who cherishes every opportunity to partake in her children’s excitement. She counts down, “Three, two, one!

Hide, Lily,” five-year-old Jireh shouts to his little sister. “We’re playing hide-and-seek!” Jireh՚s pudgy cheeks light up with joy and his eyes sparkle as he constantly invents new hiding places. Meanwhile Lily giggles, waddling with her arms wide open, a big rosy smile bulging from her gleeful cheeks.

Erin and her children live with a rare genetic disease called x-linked hypophosphatemia (XLH), a hereditary form of rickets. Along with four of her eight siblings, Erin was born with the x-linked dominant condition, which weakens bones, muscles, and teeth by depleting phosphate in the body. Chronically low phosphate levels contribute to a range of symptoms including short stature, slow growth, bone and joint pain, muscle pain, a waddling gait, tooth abscesses, and dental pain. Lately however, Erin can hardly notice the bowing of her children՚s legs beneath them as they run. Occasionally they trip and topple over, but their growth and development have become easier in many ways than what Erin endured.

Erin dealt with plenty of issues growing up, longing for a “normal” life while enduring corrective surgeries to straighten her bones as she grew. The operations varied in severity and regularity, but always impacted young Erin. “It was embarrassing.” Erin speaks of her childhood with sadness. “I felt so jealous of all the kids around me because they could run so smoothly. And when they ran it didn’t hurt.” A wistful exasperation stretches through her voice. “It felt like they were just flying across the field, and here I am struggling along, trying to get across the grass.

Whenever Erin underwent surgery, healing took significantly longer because of XLH. “I learned to be very grateful for the ability to walk, especially after a long spell of healing. Just being able to get around was a gratitude-filled activity, especially when I saw those who would never get that chance to get out of their wheelchair.

During the winter, Erin didn’t want to be stuck in the house, so she bribed her brothers and sisters who could walk to bring her a sled. She would drag herself all the way up the hill with only her arms before sledding down. “It was very exhilarating, just for a few split seconds,” she reminisces, “and then I was snapped back to reality.

Erin’s father wanted to play physically with his children, even those with XLH, and they feared letting him down. He would bring them all out to play football and shout, “Come on, I’m running circles around you guys. Try harder!” He didn’t realize how his disappointment would affect their confidence, which was especially difficult for the boys because of his higher expectations of them. But his pressure also became a form of motivation, giving all his children a bit of umph, insisting, “You can do this!

Though our structures were not strong physically, the experience did make us tougher mentally, I believe, and our immobility forced us to search for what we could do. Our predicament stretched our imaginations and gave us all a hidden drive to push forward.

Sadly, as Erin matured, she fell into a deep depression. Her body felt sick, constantly overwhelming her with stomach aches and headaches from a combination of XLH and severe food allergies she had yet to recognize. She felt afraid, socially anxious, and angry. “Life was just beating up on me. I felt no one could ever love me. For many years I begged God for help but had little hope.

Perhaps an answer to her prayers, Erin met Jacob at the age of 25. “I fell in love with Erin’s spirit right away,” Jacob reflects. The two frequently strolled through the peach orchard together to escape the family commotion. Erin hardly believed this man could be interested in her, as unattractive as she felt at the time. “Jacob was one of the first people to listen to me and believe in me. Despite feeling unattractive, smelly, and sick all the time, he stuck with me through it all. He helped me to improve my self-image and my health.”

The couple married and became pregnant with Jireh, who was born without complications. But Erin՚s health was still in limbo. The couple tried to get pregnant again, to give Jireh a sibling, but they experienced four consecutive miscarriages, each adding to the toll of emotional devastation.

Throughout her life, Erin had struggled to find a way to improve her health and manage her XLH, since there was no treatment at the time. She ingested loads of calcium and phosphate supplements to try to replenish her body’s constantly dwindling supply, but the supplements came with plenty of side effects, disrupting internal organs such as the thyroid, parathyroid, kidneys, and gut. Jacob, after much observation, deduced that dairy products were an unfortunate cause of sickness for Erin, and she learned to avoid lactose. Picking up on the need for dietary advice, she visited a naturopathic doctor, who encouraged Erin to eat more nutritious, whole foods. The diet helped Erin feel better and recover more quickly.

The changes were so dramatic, I couldn’t even believe it was happening,” she recalls. “The turnaround was so fast. My pains went away. The mood swings, anxiety, problems with my monthly cycle, the smelliness…my quality of life today is so amazing.” With better health, Erin became pregnant again, giving birth to Lily, Jireh’s new younger sister.

While it was a struggle for Erin to give birth to Lily, her next challenge loomed in the near future. Jireh and Lily both had a 50% chance of inheriting XLH. “When we found out Jireh had XLH, we expected it. We got to have one,” Erin anticipated. “When I became pregnant with Lily, I said, ՚I have a good feeling about this one. I think she won՚t have it.՚ But nope, she got it too.” Jireh՚s body reacted poorly to the phosphate supplements, and his kidneys calcified badly. His digestive system became a wreck with constant diarrhea, nutrition, and absorption issues. Erin watched in despair as her son became entirely sluggish, inactively languishing around.

In utter desperation, Erin and her husband looked online and discovered a clinical trial to treat XLH. People with XLH experience increased activity of the FGF23 gene, which then prevents the kidneys from reabsorbing phosphorus and leads to low levels of phosphorus in the body. The trial implemented a human immunoglobulin treatment, which uses an antibody to block FGF23 activity and helps restore phosphorus absorption in the kidneys, allowing phosphorus to be deposited where it is needed in the body.

Jireh started taking this same medicine at the age of four and the effect has been astounding. Two years into treatment, Jireh is the first in his family with XLH to see his phosphate levels come back to normal. As a result, his bone plates are meeting properly. Once challenged to walk with dramatically bowed legs, now Jireh is growing taller and straighter. He has energy again and can eat foods that his poor gut couldn’t handle before. “He’s getting into trouble now, which is amazing, because now he՚s doing things that a five-year-old should do. He՚s running and jumping now, which he never used to do.” The whole family has started using the medicine, and they are all seeing improvements in their condition. “My grandma, she is 87. She’s the oldest person on the medication now,” Erin proudly proclaims.

Erin continues to find solutions with a positive outlook, constantly working to improve herself and her family’s situation. She also has experienced difficult side effects of her medicine, but she continues to monitor how the drug can be most helpful to her and her children. Remembering her own childhood, Erin encourages Jireh and Lily without expressing any disappointment, and she helps Jacob use an empowering voice as well.

Erin watches as her son builds a giant ramp over which to launch his toy car. At first he starts small with a couple books, but with each success he builds the ramp higher and higher. Jireh gears up his car while Lily looks on with anticipation.

Test one!” calls out Erin.

Actually, this is like test five,” responds the little engineer as he launches the car forward.

With a proud smile, Erin fills with love and appreciation. She sees Jireh and Lily blossom in ways that were much more difficult for her as a child. But now her children benefit from loving encouragement, revitalizing nourishment in their diets, and a medicine that is helping to restore strength to their bones. Erin’s optimism for her children spills forth as she says, “Let’s not look at what they can’t do. Let’s look at what they can do and what they’re going to do.