Seldom-used blood test helps save northwest suburban girl's life

A northwest suburban family is sharing their story after a blood test saved their daughter's life.

Looking at Sabrina playing with her brother, she seems like any other healthy 7-year-old. But a year ago she began losing weight and had unexplained fevers. Doctors tried to diagnose her but came up with nothing - until she went to Lurie Children's Hospital.

"This was probably the hardest thing that we've experienced as parents," said mom Nicole. "You don't have control over the situation. You are just watching your baby hurt."

Doctors at Lurie ordered a seldom-used blood test known as the Karius test. A single blood draw is run through high computing machines that test for more than 1,000 germs and return results within a single day. The technology uses DNA sequencing to identify unique genetic material that microbes leave behind in blood.

Dr. Bill Muller, with Lurie Children's Hospital, said the hospital has had some success with the test in patients who have infections that are difficult to diagnose.

"And in (Sabrina's) case, because we had some concern that she had some kind of genetic predisposition for infection, we wanted to look for as much as we could look for," he said.

Sabrina was diagnosed with a rare genetic disease that could have taken up to six weeks for the lab to find using traditional methods. She's still on medication for the condition a year later and will be indefinitely, but she'll be okay with treatment.

"So we were happy to find an answer, to figure out what was going on" Nicole said. "It probably took about six months to find our normal again."

"I feel more energetic now and I can jump and play with my friends now," Sabrina said.

Only about 50 institutions nationwide use the Karius test right now because it's expensive and not always covered by insurance. As a result, doctors usually only order it for critically ill patients.