O’Neal Best finally got a chance to say thank you Thursday night to a man who helped save her life.
The 13-year-old Crayton Middle School student did it simply by smiling, saying hello and giving Dr. Thomas Caskey a long-delayed hug.
Last time they were in the same vicinity, she couldn’t speak. She wasn’t quite a year old when a team led by Caskey in Houston made the difficult diagnosis of a rare genetic condition that threatened her life.
Caskey, a USC graduate, returned to his alma mater this week to speak at a symposium on genetics counseling. Ironically, diagnoses of cases such as O’Neal’s, while still difficult, are more common these days because of rapid advancements in genetics testing.
But 12 years ago, her case was one of those special ones that reminds doctors why they got into the medical field. Dr. John Belmont, who worked under Caskey and did the actual diagnosis, still keeps a photo of O’Neal on his desk.
O’Neal was a healthy full-term newborn, according to her mother, Rebecca Best. Four months later, as she was being weaned from breast milk, she began having all kinds of problems. Broadly, it was called “failure to thrive.” Her little body simply wasn’t taking in and retaining nutrients, and she had constant diarrhea. Failure to thrive can lead to death. O’Neal was a very sick child.
Her local doctors tried the typical formulas and medications to treat her symptoms. “We were all scratching our heads,” Rebecca Best said. “We tried a million different formulas. Nothing worked.”
Then one day at work, her husband, Jim Best, mentioned the heart-breaking frustrations to a coworker. As it happened, that coworker was John Caskey, and his brother was a noted expert on genetic disorders. John suggested the Bests contact his brother in Houston.
The Bests’ pediatrician knew of Thomas Caskey’s work and was all for trying anything at that point.
A few phone calls later, the family was off to Texas Children’s Hospital.
“I was chair of the department, and I turned to the smartest of the smart, John Belmont,” Caskey recalled.
Debates over what was causing the problem – a blood disorder or a metabolic problem were the top candidates – even led to the “firing” of one of the other doctors on the team. Belmont was certain the problem was metabolic, and a battery of tests hinted at sucrase-isomaltase deficiency, a rare genetic disorder discovered in 1960.
People with the disorder can’t break down the common sugars sucrose and maltose. In addition to the formula’s sugars, Rebecca had been serving her daughter applesauce, contributing to the problems.
Researchers now estimate 1 in 5,000 people of European descent might have sucrase-isolmaltase deficiency. But the severity of the disorder varies remarkably, and the problems tend to decrease as children age. Caskey suspects many infants with the condition in the past either grew out of it or died from it without being diagnosed. Genetic testing makes it less difficult to diagnose now.
After O’Neal’s diagnosis, doctors changed her formula to get rid of the sickening sugars. She gained six pounds in a month, and she’s never looked back healthwise.
“She’s still tiny, but she’s doing great,” Rebecca said. “She’s a very happy and normal kid, but we certainly didn’t start that way.”
Caskey was thrilled to finally meet O’Neal after communicating with her parents for years. He beamed when she told him about her strong performance in the classroom.
Told she was leaning toward a medical career, he predicted she would make a great pediatrician.
“It’s just a joy,” Caskey said, looking back 12 years ago. “It was one of those successful cases, so you always remember those.”