Prenatal testing gave the family an early indication there may be trouble.

Doctors told Stephanie Conner that she had been infected with the cytomegalovirus, known as CMV, which commonly causes no symptom. But fetuses contracting the virus from their mothers have a one in five chance of developing serious health problems, the CDC notes. In Madeline’s case, doctors worried she would have brain damage, blindness, deafness and trouble with her heart and liver.

Stephanie and Joel braced for the worst.

Instead, Madeline’s biggest medical issue was her near total deafness. One eye showed signs of mild scarring, an indication of some potential damage.

She wears hearing aids in both ears. With them, and the constant instruction from her parents, she has been able to learn some speech.

Madeline, who is nearly 2 years old, is the first person in the USA to take part in a new Food and Drug Administration-approved study of stem cell treatment of sensorineural hearing loss. Children’s Memorial Hermann Hospital in Houston and California-based Cord Blood Registry will eventually enroll another nine children in this first phase of the study.

The process is simple: Doctors inject the children with stem cells from their own stored umbilical cords. Because it is the patients’ own blood, there is little chance the treatment will produce side effects.

In theory, the treatment will adjust patients’ immune systems to encourage their bodies to repair themselves.

The only other available treatments for Madeline’s kind of deafness are hearing aids and cochlear implants.

“I’m expecting really good results,” Stephanie Conner said. “I feel like God put this here in front of us for a reason.”

Madeline’s parents have a reason to be cautiously optimistic. Two of three preliminary tests after the treatment in January showed improvement in the girl’s hearing, the family said. The Conners will head back to Texas in January, to get a more detailed assessment of Madeline’s improvement.

Now, the LaBelle family hopes medical science will deliver another round of news verging on the miraculous: a stem cell cure (or partial cure) of Madeline’s hearing loss.