Shelby Valint’s birth in August 2000 — the second of eventually four girls — went off without a hitch. Her mother carried to term with no complications and within 24 hours both mother and daughter were safely and happily on their way home.
“I thought everything was fine,” said her mother, Renee Valint.
But when the Phoenix girl was just a few months old, Renee noticed that Shelby wasn’t progressing. Shelby had difficulty holding her head up and her body was generally limp. As time passed, Shelby had difficulty walking, talking and swallowing food.
“We were waiting to see if this was something she would outgrow,” Renee said.
But while Shelby’s brain developed, her physical condition worsened to point of needing a wheelchair.
Shelby and her family began what would become a decade-long search for a diagnosis. Shelby visited countless doctors and underwent numerous examinations and tests at medical facilities across the nation.
Anesthetized nearly a dozen times, her tests included multiple brain scans, nerve conduction studies and muscle biopsies, all of which came back negative.
“The doctors could not discover what was wrong. They just put their hands in the air,” Renee said.
Eventually, Shelby and her family found Dr. Vinodh Narayanan.
“We met Dr. Narayanan, and I knew it was going to be different,” Renee said. “He was very interested in her case, and I knew he wasn’t going to be just like one of the other doctors. He was going to stick with her to the end.”
Shelby’s case puzzled even Dr. Narayanan for several years. “We suspected some things, but we did not have an exact diagnosis,” he said.
Shelby continued to deteriorate to the point that her mother feared the worst. “We were so worried that we were never going to find an answer. The hardest part was not knowing what was wrong,” said Renee.
Meantime, technologic advances in whole genome sequencing were making it easier to apply the techniques to patient care. Sequencing that once took over a decade and nearly $3 billion could now be completed in a matter of weeks, and for a few thousand dollars.
Dr. Narayanan felt Shelby was a good candidate for WGS. TGen scientists sequenced her genome, and the analysis revealed a problem in a gene which codes for an enzyme critical for the production of dopamine, a brain chemical responsible for movement, muscle control and balance.
In December 2010, Shelby began taking drugs often prescribed for Parkinson’s disease, a disorder of the nervous system associated with diminished dopamine.
Within a few weeks, Renee noticed that Shelby was getting stronger. She could hold her head up. Her speech was clearer. She started doing more things on her own. She didn’t use her wheelchair as much.
“It happened so quickly. It was amazing,” Renee said. “She got stronger and stronger, and we just watched her flourish.”
One day, Shelby took her mother’s hand, walked out the front door and walked down the street. “That’s when I thought, this is a miracle,” Renee said.
Shelby’s case inspired TGen officials to establish the Center for Rare Childhood Disorders (C4RCD).
“Shelby, to us, demonstrated that this can be done,” said Dr. Matthew Huentelman, Co-Director of TGen’s C4RCD. “What I hope we can do is to provide answers for these families. We strongly believe that, for a lot of these rare childhood disorders, the root cause is going to be found in their genome.”
“We’re not trying to stop there, at the genetic diagnosis. We’re trying to provide even more information back to the physician, back to families, about how we might now attack this disease,” Dr. Huentelman said. “It gets us to a new foothold. It’s a new answer for these families, where in a lot of cases they’ve had none.”