A Rare Genetic Diagnosis Gives Arturo’s Family Answers—and Hope

Stanford Children’s experts combine advanced genetic testing and rare-disease expertise to guide care for MED13-related disorder

At 3 years old, Arturo Alvarez-Krystosik fills his home with music. He loves playing the keyboard, harmonica, and drums, and he is constantly singing. His mom, Amy Krystosik, says music has become one of the clearest ways he expresses himself.

“He doesn’t have many words, but when he sings…” Amy says.

Arturo also adores his 6-year-old sister, Anna Sofia, whom he follows “day and night.” He loves the family dog, Bunny, and enjoys spending time with a friend from school. Today, Arturo is growing, learning, and attending school with the support of an aide—showing his family and care team how much he understands.

But when Arturo was an infant, his family was searching for answers as concerns emerged one by one, affecting his feeding, growth, vision, movement, and development.

Arturo was born small at Lucile Packard Children’s Hospital Stanford, and Amy says he experienced low blood sugar, or hypoglycemia, shortly after birth. By 2 months old, he was not gaining weight as expected, a condition often called failure to thrive, and his family began seeing multiple specialists.

A major clue came through the Aerodigestive and Airway Reconstruction Center at Stanford Medicine Children’s Health, where specialists evaluate how a child’s airway, lungs, digestive tract, and feeding work together. Amy learned that when Arturo drank milk, some of it entered his airway and lungs rather than traveling safely to his stomach. This swallowing problem, called dysphagia, was causing inflammation in his lungs and placing him at risk for recurring respiratory problems. It also helped explain Arturo’s earlier visits to the emergency department.

Feeding-tube support became essential.

“I don’t think he would have survived without the feeding support provided by his NG-tube and G-tube,” Amy says.

A gastrostomy tube, or G-tube, is placed through the abdomen into the stomach. A nasogastric tube, or NG tube, passes through the nose and into the stomach. For children who cannot safely consume enough nutrition by mouth, tube feeding can be lifesaving.

At the same time, other concerns became apparent. Arturo’s eyes moved back and forth, a condition called nystagmus. An ophthalmology evaluation at Stanford Children’s also showed pale optic discs, raising concerns about his vision. In addition, he appeared very weak and “floppy,” a sign of hypotonia, or low muscle tone.

During his first months of life, Arturo saw several Stanford Children’s specialists and received physical and occupational therapy for developmental delays. Still, his family did not have a single diagnosis that could explain why so many parts of his body were affected.

That changed when Arturo met a member of the Genetics team, Christina Tise, MD, PhD, a medical and biochemical geneticist and director of the Reproductive Genetics Clinic at Stanford Medicine Children’s Health.

Finding one answer behind many symptoms

When Dr. Tise evaluated Arturo at 7 months old, she saw a baby with complex needs involving multiple body systems. He was babbling but could not sit independently. He also had feeding challenges, vision concerns, poor growth, and global developmental delays.

Because his symptoms affected several parts of the body, Dr. Tise recommended a broad genetic test called exome sequencing. Some institutions begin with targeted gene panels, which examine a defined set of genes and may not include genes only recently associated with disease.

“Gene panels can lag behind as new disease associations are identified and panels need to be updated,” Dr. Tise says. “The fact that we did exome sequencing was important.”

Exome sequencing analyzes the protein-coding regions of a person’s genes, where many disease-causing variants are found. Stanford’s clinical laboratory performed trio exome sequencing, analyzing Arturo’s DNA alongside DNA from both of his parents.

The test identified a disease-causing change (sometimes referred to as a pathogenic or likely pathogenic variant) in the MED13 gene, giving Arturo a diagnosis of MED13-related disorder.

“The MED13 gene provides instructions for making a protein that helps regulate the expression of many other genes,” Dr. Tise explains. “Because this regulatory protein has a broad role in development, a disease-causing variant can affect multiple organ systems and lead to congenital differences, sometimes with significant effects.”

The variant identified in Arturo was de novo, meaning it was not inherited from either parent.

For the family, the diagnosis brought clarity.

“The day I got the diagnosis, I kept taking care of the kids,” Amy says. “I was a mom. Then, at night, I walked and walked.”

As an epidemiologist, Amy quickly began reading the limited research available. MED13-related disorder is exceptionally rare and was first described in the medical literature only recently. At the time, the published cases Amy found involved children aged 3 or older, making Arturo potentially the youngest patient diagnosed with the condition described in the literature.

Receiving the diagnosis during infancy provided Arturo with an opportunity to begin recommended therapies and support much earlier. At the same time, the newness and rarity of the condition meant that no one could tell the family precisely what Arturo’s future would look like.

People diagnosed later in childhood or adulthood may not have had access to therapies guided by an early genetic diagnosis. As a result, there is a limited basis for understanding what may be possible when a child receives coordinated care and developmental support beginning in infancy.

Still, the diagnosis gave the family something they had not had before: a name for what Arturo was experiencing and a way to begin planning.

“Diagnosis can be the beginning, not the end,” Amy says.

“Not every family receives an answer,” Dr. Tise says. “Some families are told to return in three to five years as knowledge and testing evolve. At Stanford Children’s, we can offer broad genetic testing and connect families with research efforts that may help identify a diagnosis sooner.”

The Genetics team at Stanford Medicine Children’s Health has access to advanced clinical testing and works closely with an in-house laboratory. The Genetics team includes more than 10 genetics providers with a range of expertise, allowing them to evaluate rare and inherited conditions across ages.

When standard clinical testing does not provide an answer, the team can also connect eligible families with rare-disease research efforts and national collaborations, including the Undiagnosed Diseases Network and the GREGoR Consortium.

For Amy, Dr. Tise’s support did not end when she delivered the test results.

“She didn’t just give us the diagnosis,” Amy says. “She asked, ‘What do you want to do now? How can we support you? Let’s do it together.’ I don’t know anyone who engages at that level. She doesn’t stop at a diagnosis.”

Coordinated care across Stanford Children’s

Once Arturo had a diagnosis, Dr. Tise and the rest of his care team could better coordinate support around his needs.

His care at Stanford Children’s has included experts from medical genetics, aerodigestive, gastroenterology, pulmonology, otolaryngology, orthopedics, ophthalmology, audiology, neurology, developmental and behavioral pediatrics, the Complex Primary Care Clinic, feeding therapy, physical therapy, occupational therapy, and speech therapy.

The early focus was survival and stability: safe feeding, nutrition, growth, lung health, and vision. Over time, the goals expanded to helping Arturo build strength, communication skills, mobility, school readiness, and independence.

During Arturo’s care journey, the family also began working with the Complex Primary Care Clinic at Stanford Medicine Children’s Health, where Amy says support from Jean Chia, MD, and the broader team made a major difference.

“You can call them anytime—nights and weekends—and talk to a physician on call,” Amy says. “They help you manage care in the best possible way. They advise you when you need to bring your child in and when you can comfortably manage care at home.”

For a child with a complex condition and many specialists, Amy says, that support is essential.

“They help manage all the specialties, the paperwork, school—everything,” she says.

Because Arturo needed frequent access to the hospital and his specialists, the family moved closer to Packard Children’s Hospital in Palo Alto during the first two years of his life.

“When we needed to be very close to the hospital, we moved closer to Stanford (Children’s),” Amy says.

During surgeries and hospital stays, the family also found comfort in spaces and resources beyond Arturo’s hospital room, including books, the library, a sensory room, a playground, and the chapel.

Sometimes, Amy says, she simply needed a brief break from the hospital environment.

“One time, I needed to get out of the hospital, so I walked to Stanford Shopping Center for a coffee,” she says. “That was nice.”

Those resources and opportunities for respite helped make long days at the hospital more manageable for the entire family.

A child transformed by early support

At a follow-up appointment, Dr. Tise saw a very different child from the baby she had first evaluated.

Arturo was wearing glasses and could visually follow people and objects. He was communicating more, standing on his own, gaining weight, and growing well. He was also attending school with an aide and demonstrating that he understood much more than he could express verbally.

“He was not the child I expected to see at follow-up, given how he presented initially,” Dr. Tise says. “If you did not know his diagnosis, you might not realize how many therapies and how much support it took to help him make that progress.”

There is currently no cure for MED13-related disorder. Treatment focuses on supportive care, appropriate therapies, ongoing monitoring, and helping each child reach their fullest potential.

For Arturo, that support—combined with his family’s advocacy—has helped him become stronger, safer, and more engaged with the world around him.

From diagnosis to advocacy

After Arturo’s diagnosis, Amy wanted to help other families facing the same rare condition. She founded the MED13 Foundation to support families, build community, advance research, and help accelerate the path toward possible treatments. Amy hopes research will one day lead to treatments that can help children like Arturo become more independent and thrive.

For Dr. Tise, being able to give Arturo’s family an answer was especially meaningful. “Giving his parents an answer meant a great deal,” she says.

For Amy, the diagnosis was not the end of the road. It was the beginning of a new chapter—one shaped by coordinated care, therapies, research, advocacy, and hope.

“For families navigating a rare diagnosis, every story is different, and everyone brings a different perspective. Stay open to the possibilities. If one path closes, keep looking for the next one. There is always another way forward,” Amy says. “Our family feels very fortunate to be at Stanford, where so many specialists have helped guide us and given Arturo opportunities to succeed. We know that level of support is not available to every family,” she concludes.

Learn more about Genetics and the Complex Primary Care Clinic at Stanford Medicine Children’s Health.