Persistence leads to diagnosis of ultra-rare disease
Three-year-old Liam Mattson is always on the go. His parents say that is in large part due to the expertise and advocacy of pediatric specialists at UI Stead Family Children’s Hospital.
When Liam Mattson visits University of Iowa Stead Family Children’s Hospital, it’s not unusual to see the 3-year-old running confidently down corridors or happily typing away on his doctor’s computer.
Daniel Hinds, MD, MS, doesn’t care one bit. The pulmonologist says Liam has come a long way since he first saw him nearly a year ago.
“When I come into clinic and he’s bouncing off the walls because he has so much energy, that’s great,” Hinds says. “I’m happy to see that because it means he has enough energy to do the things he wants to do and is doing well enough with his underlying disease that he can have fun and enjoy the day.”
The disease Hinds is referring to is an extremely rare genetic autoinflammatory disorder: STING-associated vasculopathy with onset in infancy (SAVI). Fewer than 100 people have been diagnosed with SAVI, and Liam is thought to be the first premature baby to have it.
Liam’s mom, Taylor Mattson, credits her son’s medical team for not giving up on finding a diagnosis and connecting the family from Solon, Iowa, with specialists at the National Institutes of Health (NIH) in Washington, D.C.
“I can’t tell you how many times we were told out in D.C. that we were so lucky to have the care and providers we have here at Iowa—especially Dr. Daniel Hinds and Dr. Polly Ferguson,” Mattson says. “If it weren’t for them diagnosing him so early, who knows where Liam would be now. We truly have the best of the best medical professionals at this hospital.”
Liam was born at 27 weeks and spent 167 days in the UI Stead Family Children’s Hospital neonatal intensive care unit (NICU), during which he faced multiple complications and setbacks.
After Liam came home, Mattson says she worried that he wasn’t progressing as quickly as he should in some areas, including continued low blood oxygen levels and obstacles with eating, leading to a hard time gaining weight. These are all symptoms that could be associated with him being born prematurely.
“But something just didn’t feel right,” Mattson says. “And they listened to me.”
After Liam developed a respiratory virus in spring 2023, Anthony Fischer, MD, PhD, noticed clubbing, or swelling, in Liam’s fingers. He suspected it could be from cystic fibrosis or possibly other forms of rare lung disease. After Fischer consulted with Hinds, Hinds ordered a CT scan of Liam’s lungs, which was performed the day of their first clinic visit. After reviewing the images with Mattson in clinic, Hinds decided to order genetic testing.
That’s when they learned Liam had the autoinflammatory disorder SAVI. Inflammation normally occurs when the immune system sends white blood cells to fight or repair injury or illness. Disorders such as SAVI can cause excessive inflammation, which can damage the body’s own cells and tissues. The lungs are particularly vulnerable, which is especially concerning for Liam because of the lung problems he already dealt with from being born prematurely.
“I had seen a patient during my fellowship with SAVI, but I wasn’t the primary physician, so I wasn’t aware of all the aspects of the disease,” Hinds says. “So, I called Polly and asked her to help. It’s great to have colleagues like her—it’s helpful to phone a friend.”
Rheumatologist Polly Ferguson, MD, had previously cared for a patient with SAVI—although the disease didn’t have a name at that time. It’s only been a decade since SAVI was discovered, and Ferguson has authored papers with one of the doctors who identified it, Raphaela Goldbach-Mansky, MD, MHS, chief of the National Institute of Allergy and Infectious Diseases Translational Autoinflammatory Disease Studies Section.
“So, Dan called a friend, and then I called a friend,” Ferguson says. “I strongly encouraged the family to bring Liam to Washington, D.C., to see Dr. Goldbach-Mansky. The NIH was willing to see them right away, which was really nice because the disease can be so aggressive.”
The Mattsons spent three days at the NIH in January, during which Liam had 19 appointments with SAVI experts as well as specialists in pulmonology, dermatology, cardiology, and gastroenterology.
“Liam was such a champ,” Mattson says. “And as overwhelming as it was at times since getting the news, when we came home, I felt like I could breathe again. I really appreciated our doctors reaching out to their colleagues here and at other hospitals. I always felt like they were doing whatever they could for Liam’s best interest.”
Before the Mattsons even traveled to Washington, Ferguson and Hinds worked together to develop a treatment plan for Liam.
“We worked to get the medicines that he would need approved and, shockingly, we got them all approved quickly, even though they’re not FDA approved for use in this disease because there is no FDA-approved medicine for it,” Ferguson says. “After their trip, the NIH agreed with the Iowa therapy plan, and it turned out we actually could use a little less of the medicines than we thought based on the NIH in-depth analysis of how his immune system was working.”
While in Washington, the Mattsons met a few other families with children who have SAVI. Taylor Mattson says it was comforting to speak to other parents who were in a similar situation.
“It’s hard when you don’t have that community,” Mattson says. “I posted to a lot of different rare disease and autoinflammatory groups, but it’s nice to talk to people who are really in the middle of the same thing we are.”
As Iowa’s only nationally ranked children’s hospital, with six pediatric specialties listed in the 2023-24 U.S. News & World Report ranking of “Best Children’s Hospitals,” doctors at UI Stead Family Children’s Hospital aren’t strangers to diagnosing and treating rare diseases.
“Liam is one example of those really rare, really unique patients,” Hinds says. “He’s a good example of if a square peg doesn’t fit into a round hole, don’t try to make it fit. Look for something else that fits it better.”
Ferguson says her experience with SAVI before it was even identified highlights how fast medicine is changing.
“There’s been such an explosion in our understanding the genetics for some of these rare immune-mediated diseases,” Ferguson says. “So, our ability to make a definitive diagnosis has improved substantially. And that helps point us to the right medicine to use. For example, SAVI is interferon driven, and we know that if we block the interferon pathway, that’s going to be the best way to help.”
Ferguson and Hinds say having a resource such as UI Stead Family Children’s Hospital is critical for Iowans and residents in surrounding states.
“We have a lot of amazing people here who have incredible expertise,” Ferguson says. “This allows patients to stay in their community and get really good care, which makes life just that much less complicated when you have a child with a rare disorder that requires a lot of medical attention.”
Hinds agrees, adding that as Liam’s case demonstrates, they also can call on colleagues at other facilities.
“The pediatric community is pretty small, so it’s not hard to call someone and say, ‘This is my patient, what would you do?’ Or, ‘Am I missing something?’” Hinds says. “You can kind of informally get that help, especially if a family isn’t able to travel for a second opinion. Being able to receive this level of care locally is so helpful for people who otherwise may not be able to get these answers or get these life-altering medications and therapies.”
Liam continues to be monitored and receive therapy at UI Stead Family Children’s Hospital and University of Iowa Health Care clinics. His parents say they are proud of his resiliency.
“He’s also very sweet,” says Liam’s father, Brady Mattson. “And he’s always on the go. He just never stops.”
Liam recently started attending preschool a couple of days a week, which his mom says has been good for him.
“He’s been like a whole new kid,” Taylor Mattson says. “It’s really brought out his speech and development. The overall routine has just been amazing for him.”
Taylor Mattson says the staff at UI Stead Family Children’s Hospital has become like family, and it’s hard to find the words to express how grateful they are for their care and advocacy of Liam.
“I don’t know what Liam’s outcome would have been without them, given that he was born at 27 weeks and then having a rare disease,” Taylor Mattson says. “They give us hope, and we will be forever grateful that this hospital is literally in our backyard.”
Sharing NICU stories and advice through podcast
Taylor Mattson’s son, Liam, spent 167 days in the neonatal intensive care unit at University of Iowa Stead Family Children’s Hospital. And during that time, she learned a few things about being a NICU mom.
Mattson and a fellow mom she met in the NICU, Masse Poetting, recently launched the third season of The Real Mamas of the NICU Podcast, where they “get vulnerable, serious, share laughs, and bring on guests to help give insight to the world of being a NICU parent.”
“We decided that once we were out of here to do something like this to give moms something to listen to,” Mattson says. “It’s also therapeutic for us to talk about our experiences.”
Liam is now 3, and Taylor says she would offer two pieces of advice for other NICU parents.
“Prioritize taking care of yourself. I know that’s easier said than done. I had a nurse who told me that the best mom is going to be the one who takes care of herself. So, I left, got my nails done, just briefly, and came back. But I felt so much better. So, take care of yourself.
“And then the other thing is to lean on the community of parents who are also there. That was my saving grace, making friends who are now family to us and understand exactly what we’re going through when not everyone does.”
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