Disgraceful Darlene Phillips who was the boys primary caregiver dumped the helpless youngster in a park with a note, hoping someone would pick him up, back in April 2010.
Severely disabled Gerren Joseph Isgrigg, was blind, deaf suffered daily seizures and had no functions in his arms and legs and had to be fed through a tube and left helpless he died when no one helped the boy.
Dallas Police have said he was small for his age, weighing just 28 pounds.
The boy's father, Jerry Isgrigg, told the Dallas Morning News finds the story unbelievable.
He said: "I can't fathom it. Honestly, I just can't fathom a person doing it, let alone a family member doing it and let alone somebody who's actually been caring for him day in and day out doing it.
"If it's too much to handle, there are ways to find me. You can't tell me they couldn't find me."
But her husband blamed stress for her actions.
Patrick Phillips said: "From our conversation today, she knows it was a big mistake. She never planned on this to happen.
"She thought somebody would come along right away and he would be taken care of. Stress does terrible things."