Rare condition caused cardiac arrest in 10-month-old boy; mom now an advocate for children with PPA2 deficiency

Strange breathing from a baby monitor in her 10-month-old son's bedroom woke up Kathleen Simonetti.

She rushed to his room to find Noah limp and blue early that morning.

Simonetti, 38, a former volunteer EMT, and her husband, Steven Simonetti, 36, immediately began chest compressions on Noah before paramedics arrived.

Noah later went into ventricular fibrillation and paramedics shocked him twice with an automated external defibrillator.

"I had never actually had to perform CPR on a patient up until my son," Simonetti said of her seven years as an EMT.

Since that day in April 2022, she's been on a journey of advocacy for Noah, who had another cardiac arrest before age 2, and before he was diagnosed with a rare gene mutation, inorganic pyrophosphatase, or PPA2 deficiency.

One year after creating her nonprofit Heart of PPA2, Simonetti is continuing to spread awareness about the condition, which she and experts said could be misdiagnosed as sudden infant death syndrome (SIDS) or sudden unexplained death in childhood (SUDC).

A difficult diagnosis

During Noah’s first cardiac arrest, he was rushed to Stony Brook University Medical Center where he was stabilized and diagnosed with rhinovirus and enterovirus, even though he had shown no symptoms or any heart conditions.

"They said with any virus, it can cause inflammation in your heart," Simonetti said. "So that's what they were assuming it was."

Noah was transferred to NewYork-Presbyterian Morgan Stanley Children's Hospital in Manhattan where he underwent surgery to have an implantable cardioverter-defibrillator, or an ICD, placed as a precaution. Doctors also tested Noah for a panel of cardiac diseases and conditions, all which came back negative.

But the nightmare was not over for the Simonetti family.

Eight months later while Noah was suffering from pneumonia, the Simonettis brought him to urgent care and then to the emergency room when they noticed he was breathing rapidly.

Noah went into cardiac arrest three times at Stony Brook University Hospital — a total of four times before he was 2.

"In our heads we were like, this cannot be happening again," Kathleen Simonetti said.

Due to his pneumonia, Noah was intubated for about one week. Once he breathed on his own, he spent another 18 or so days in the hospital to recover and relearn how to eat, sit, talk and walk.

"This is not normal," his mother recalls telling doctors. "There has to be a reason that this keeps happening."

Doctors then agreed to have Noah screened for a wider genetic disease panel.

Simonetti said she had a standard prenatal genetic screening when she was pregnant with Noah, but the results came back clear.

Medical answer received

Over a month later, just after Noah’s second birthday, Kathleen Simonetti received an answer. 

At 5 p.m. on a Wednesday, Simonetti received the results through an email: ‘PPA2 - related sudden cardiac failure.’ "

"I was at work when I read it, and I just immediately started crying hysterically," Simonetti, who was pregnant with her daughter, said. "Especially when it's in your email about five o'clock on a weekday and doctors are no longer in the office, for you to call."

The genetic panel showed Noah had a mutation in the PPA2 gene, which controls energy production by mitochondria.

When the body undergoes stress, organs that require the most energy, such as the heart or brain, are overworked, and therefore a person can easily go into cardiac arrest.

"Ultimately it's an energy failure," said Dr. Hilary Vernon, director of the Kennedy Krieger Mitochondrial Center in Maryland.

"Mitochondria are essentially little batteries in every cell in the body that provide most of the energy that the cell needs to function ... it takes hundreds of probably, approaching 1,000 genes, to build a mitochondria."

About 1 in 5,000 people suffer from a mitochondrial disease, Vernon said. 

Stress can include illnesses as simple as a common cold. The condition can also present when alcohol is ingested or absorbed through the skin.

Experts said consuming or using everyday products such as vanilla extract, cough medicine or alcohol wipes can cause cardiac arrest. 

"Nobody's giving babies wine or beer, or anything like that, but the number of medications that contain even trace amounts of alcohol is really staggering," Dr. Amy Goldstein, an expert in mitochondrial diseases and one of Noah’s doctors at Children’s Hospital of Philadelphia, said. 

At the time of Noah’s diagnosis, only 65 people in the world had been recorded as having PPA2 deficiency. Just 10 people were living with it.

There is no cure.

The morning after they received the results, Simonetti said a team of specialists had met and reached out to the family to form a game plan on how to give Noah the best care moving forward.

Kathleen and Steven Simonetti learned they were carriers for the deficiency. When both parents are carriers, a child has a 25% chance of having PPA2 deficiency.

Their daughter Sophia Simonetti, now 2, was tested and does not have the condition. 

Support groups 

Simonetti said she looked to find support groups after Noah’s diagnosis.

The only community she found was a Facebook group with 20 members, created by Danielle Green, mother of two PPA2 deficient children in Australia.

One child had died of PPA2 deficiency before Simonetti joined the group and the other died after she became a member.

"One child passes away, and they think it's SIDS, like a crib death kind of situation," Goldstein said. "Then a second child in that family then may pass away, and at that point you have to assume something very serious and genetic is going on here."

Influencer Melissa Mae Carlton had a 9-year-old daughter and 5-year-old daughter die within two years of each other. Both had PPA2 deficiency.

"I truly believe that any time a situation like this happens, whole genome sequencing should occur in every child ... whether it's a near death event or a sudden death event," Vernon said. "We're missing not just PPA2, but many, many other of these biochemical disorders."

Goldstein said there were now about 50 families, or about 100 people, affected worldwide by the condition.

The gene mutation was only recently linked to sudden infant cardiac arrest in a 2016 publication, which noted that four siblings in New Zealand went into cardiac arrest after tasting alcohol for the first time.

A 2006 publication was the first documentation linking the PPA2 gene to mitochondrial disease.

"It just makes you wonder how many other cases are out there which could potentially be this," Simonetti said. "But it's not normal protocol for genetic screening to be performed on autopsies necessarily, unless there's like a family history."

After Green's second child died of cardiac arrest from a stomach bug, Simonetti decided to take their group more public and created a social media platform called Heart of PPA2.

On May 27, 2025, Simonetti registered Heart of PPA2 as a nonprofit organization, which provides resources for families and physicians. She also helped to have May 2 recognized as PPA2 Deficiency Awareness Day.

A typical 4-year-old

Noah is a typical 4-year-old who likes superheroes, monster trucks, Hot Wheels, and arts and crafts, and enjoys school, Kathleen Simonetti said.

"It's crazy because he's been through so much, and he just looks like a normal kid on the outside," she said.

The family said navigating life with an immunocompromised child requires support and patience.

They recently moved from Medford to Stony Brook to be closer to the children’s hospital, because he must go to the emergency room anytime he falls ill.

Noah regularly sees a team of specialists, including a cardiologist, and visits the Mitochondrial Medicine Program at Children's Hospital of Philadelphia every six to nine months.

Teachers tell Kathleen and Steven if a stomach bug or illness is going around school.

Noah is aware of the deficiency, Kathleen said, and is "very smart and wise beyond his years."

Noah and his mother even create videos on Instagram to educate others on the wide variety of products that contain alcohol, such as toothpaste, vinegar and hand lotions.

Moving forward, Simonetti said, she hopes the public can be educated about PPA2 deficiency. She encourages healthcare providers to think outside of the box when a child unexpectedly dies or has a cardiac arrest.

"People shouldn't be losing multiple children. So it's just ... if you're a doctor or a family member, to not just take the easy way out." and take the extra step when diagnosing someone, Simonetti said.

"We shouldn't have gotten to the point where my son was almost two and only then got a diagnosis," she said.