Wolf-Hirschhorn syndrome occurs in about one in 50,000 live births. Health problems can vary from child to child, but some serious impairments include seizures, hearing loss and eye malformations, as well as kidney, brain and skeletal abnormalities. Heart disease and frequent lung infections are also immune deficiencies also reported.
Patients can be denied an organ transplant for a variety of reasons, according to the American Society of Transplant Physicians. Transplantation will not be offered to those would could be harmed by the surgery itself or by the immune-suppression that is required to prevent organ rejection.
Patients with weak immune systems or a high risk of infection, such as some children with Wolf-Hirschhorn Syndrome, cannot be immunosuppressed, according to those guidelines.
Some doctors have reported that patients with the syndrome have difficulty with anesthesia because their heads and mouths tend to be small, making it hard to place a breathing tube during surgery.
Patients with severe heart disease may have an unacceptably high risk during surgery. Also, those who are not expected to live five years may also be denied a kidney transplant.
Patients with severe intellectual impairment may be considered for transplant if the benefits outweigh the harms, say guidelines.
Rivera said that during the meeting with a CHOP doctor, he said Mia would not qualify for transplantation.
"I put my hand up," she writes on her blog on the Wolf-Hirschhorn website. "Stop talking for a minute. Did you just say that Amelia shouldn't have the transplant done because she is mentally retarded? I am confused. Did you really just say that?"
Rivera writes that she was so upset that she burst into tears: "Niagara Falls. All at once. There was no warning. I couldn't stop them," she wrote.
Today, Mia cannot walk or talk yet and has a gastrointestinal tube because she is unable to eat by herself. "But she smiles and plays and recognizes us and loves her brothers," said Rivera. "They love to play with her."
Rivera said she is also convinced that research on Wolf-Hirschhorn syndrome is "pretty dated."
"There are people in their 60s and plenty of them in young adulthood in their 20s, 30s and 40s," she said.
"Any mother wants the best for her child and will do whatever it takes to get it," said Rivera, "Mia isn't to blame for this. She didn't want ask for this syndrome and all we ask for is the right to fair medical treatment."
ABC's Dr. Elizabeth Chuang contributed to this report.