Haas said her daughter never received such a test. So when her bilirubin levels spiked, Lexi began to suffer from brain damage without doctors or her parents knowing.
But the brain damage that Lexi suffered was highly specific to an area known as the globus pallidus, which is crucial in controlling voluntary movements. Consequently, Lexi is unable to move normally, but her mental faculties remain unaffected.
"Even though they look retarded because they can't move, can't talk normally, they are bright kids trapped in these bodies that don't work because of their dystonia," Shapiro said.
Lexi may very well represent the first case in which a deep brain stimulation procedure is being used to treat someone with kernicterus, brain experts said.
Because kernicterus appears to have affected this one small area of Lexi's brain so profoundly, leaving the rest relatively untouched, the idea that the electrical current delivered through a probe placed at the exact right spot in the brain is a tantalizing one.
"[Deep brain stimulation] has been successful in people with a genetic form of dystonia," Shapiro said. "Other kinds of dystonia have not responded to deep brain stimulation, and nobody knows why.
"In kernicterus we have no idea; we don't know if it's going to work," Shapiro said. "We think there is a reasonably good chance that it will work, and she's so bad off with her dystonia that the potential benefits to her outweigh the risks."
Other doctors not directly involved with the case agreed that the technique may be worth a shot.
"I suspect most of the movement disorders in these children begin at a very early age," said Dr. Jeffery Arle, a neurosurgeon at Lahey Clinic in Burlington, Mass. "They have progressive problems in their entire development period making an abrupt solution and 'fix' with [deep brain stimulation] difficult -- though not impossible to consider. ... I would not rule it out as a plausible treatment option."
But for Haas, who had been waiting for Lexi to turn 7 in order to be eligible to receive the treatment, the procedure at least offers some hope.
While the treatment will likely take between four to six months to show any evidence of effect, Haas said she believes her daughter's young brain may be able to "rewire" itself through the treatment.
"She will hopefully learn how to talk and, her doctor said, with a miracle, will learn how to walk," Haas said. "If we can get to the point where we improve her communication, [help her] go to college or hold down a job, the picture changes completely."