Every Child Matters:

Belnap Family

Seth Belnap is an energetic 6-year-old from Show Low, Arizona, ready to engage in a conversation with anyone, and a constant source of joy in his family.

When Seth was 2, his parents worried that something was very wrong. Seth still hadn’t started speaking. And worse, he kept falling; sometimes hurting himself so badly that his parents had him start wearing a bicycle helmet and his father Newell, a physician’s assistant, had to stitch him up.

An electrocardiogram indicated some abnormalities in his heart, and an MRI revealed some benign cysts in his brain. But when Seth was taken for a thorough check-up at a hospital, he seemed so happy that, his parents said, no one took any of his problems seriously.

“Seth has always been the happiest kid ever. It doesn’t matter what goes on, he’s happy,” said Newell. “He just radiates love.”

Discharged from the hospital, the Belnap’s believed their son must be fine. Still, Seth continued to fall, and failed to speak.

Not satisfied, Seth’s parents eventually took his test results to other doctors.


One doctor suggested Seth be seen by Dr. Narayanan and his pediatric neurogenetic team in Phoenix. Newell said he was impressed by Dr. Narayanan because of his intelligence and humility; his willingness to say that he didn’t know what was wrong, to consult specialist with greater expertise, and the confidence he expressed by saying he would do everything possible to find the source of Seth’s problems.

“We had been bounced around from doctor to doctor to doctor,” Newell said. “We were devastated that Seth’s condition continued to deteriorate and that nobody knew what it was. But we left feeling confident that we finally had someone who was going to help us.”

After more testing, Dr. Narayanan was highly suspicious of Mitochondrial Disease and recommended a specialist in Atlanta, who confirmed the diagnosis of Leigh’s Disease. Seth was put on a collection of vitamins, antioxidants and supplements known as a “mito cocktail,” as well as folinic acid to counter a folic acid deficiency detected in Seth’s brain.

He also recommended that TGen sequence Seth’s genome, spelling out his DNA code to see if he had a genetic defect.

Not long after Seth’s diagnosis, tests showed that his 18-year-old sister, Sydney — who has similar facial features, cognitive problems and a small stature like Seth — also has Leigh’s Disease. Sydney also was put on a mito cocktail.

Then, in March 2012, the Belnap’s older son, 15-year-old Spencer — who had excelled in school and sports — was suddenly stricken with a paralysis on his right side that left him temporarily numb and unable to properly speak. Tests showed Spencer also has a form of Mitochondrial Disease, though not as severe as the Leigh’s Disease suffered by Seth and Sydney.

“Spencer’s diagnosis threw our world upside-down,” Newell said.

Spencer also is now on a mito cocktail, as is the Belnap’s younger daughter, 10-year-old Sierra. While Sierra has not been diagnosed with Mitochondrial Disease, she is receiving medication as a preventative measure.

Nearly two years after the start of his medications, Seth is talking —and he only wears a bike helmet when he’s riding his bike.

While the Belnap children appear fine, for now, their parents continue to worry.

TGen is studying all members of the Belnap family in an effort to go beyond diagnosis. “We’re still trying to figure out what is the genetic basis of their mitochondrial disorders.”

Mitochondrial Disease is progressive. It can lead to: a loss of muscle coordination and muscle weakness; visual and hearing problems; learning disabilities; heart, liver and kidney disease; gastrointestinal and respiratory disorders; neurological problems, autonomic dysfunction, and dementia. Many children diagnosed do not live to adulthood.

“It’s such a different way to live when you have sick kids. Things that used to be important to us, aren’t,” said their mother, Becky. “Our lives revolve around taking medications and the next doctor’s appointment. We try to live each day in the moment. You’re just grateful for every day, and for the joy that they bring to us.”