The baby boy was damaged by the left brain after the doctors mistakenly diagnosed meningitis – rejecting his symptoms as a chest infection.
Freddie O'Driscoll was 11 months old when his parents brought him to hospital after he had vomited, wheezed and lethargic.
His mother, Rachel Henderson, 35, told the doctors she was afraid her son might have been struck by meningitis.
She says she even pointed to a poster in A & E that warns parents of meningitis in babies, but is told to "exaggerate."
Freddy was diagnosed with chest infection and gastroenteritis, and Rachel and her partner Tyler O'Driscol, 31, were told to take him home.
But hours later, Rachel and Tyler, taking care of her, took her son back to the hospital of good hope at Sutton Coldfield, West Mids, when his condition worsened and eventually diagnosed a bacterial meningitis.
His parents, from Tamworth, Staffordshire, are now taking legal action against the hospital after Freddy was damaged by the left brain.
Rachel full-time said, "There was a poster in A & E on meningitis in babies, and we tried to point out this and raise concerns, but we felt we just overlooked and were told we were reacting too much.
"Even when we returned Freddy to a hospital, we still seemed to be in a circle.
A doctor said he could not be meningitis because Freddy did not have a rash.
"Luckily, a doctor thought he had something sinister and organized with antibiotics and further research.
"If it was not that Dr. Freddy might not be here today.
"I'm still angry at the way the staff just felt like dismissing us as his parents.
"I may not be a doctor, but I know my son, and I knew there was something serious about him.
Rachel and Tyler, who also had another son Alfi, were worried about Freddy when he started vomiting, and on September 21, 2016, he became gray.
They pushed him back to Nadejda Hospital in Sutton Coldfield, West Midlands, at 23 o'clock when he was evaluated by a nurse.
About two and a half hours later, he was examined by an A & E physician, but the meningitis was not diagnosed.
Around 2.45 hours the following morning, employees raised fears that Freddie would exceed the four-hour waiting time in A & E and want to transfer it to a ward.
Just before 4:00, Freddie was transferred to a clinical evaluation unit after Rachel asked for a second opinion, but it was written around 6:30 in the morning.
Rachel and Freddie returned to the hospital at 6.30 pm, because they were constantly vomiting and seemed more lethargic.
He was given an intravenous antibiotic at 12.45. On September 23, before being transferred to another hospital after having undergone a lumbar puncture.
At 16.20 on the same day, the results confirmed that he suffered from meningitis and had been isolated.
Freddy has already returned home, but has been damaged by the left brain and suffers from behavioral problems.
Rachel said, "We are now faced with so many challenges that follow Freddie's disease, yet he is the most charming little boy we might want."
The couple complained to the hospital about Freddie's treatment and a serious incident report revealing a catalog of failures.
The report, published by the University Hospitals in Birmingham, NHS Foundation Trust, which now runs the hospital, finds that there is a delay in Freddie's care.
The report states that there is a "inability to investigate and diagnose a meningitis" and that "the breakdown in the relationship between Freddie's mother and the clinical team means that there is no concern about Freddie's overall condition."
Injury lawyers Irwin Mitchell are now investigating the hospital on behalf of the couple.
Attorney Lian Leighton, who represents the family, said: "Through our work, we often see the devastating effects that families can leave to the person due to meningitis.
"Awareness of signs and early detection are key to its survival.
Freddie's disease has had a profound impact on the family, and it is not fully known what Freddie's long-term effect will have on his future.
Rachel and Tyler have a number of concerns about the care Freddy has received and how they feel their concerns are being overlooked.
The Trust Report has identified issues related to delays and the way employees deal with what is clearly an extremely worrying time for the family.
"It is vital that staff maintain the highest standard of professionalism at all times, listen to families, and treat patients and their loved ones with care and compassion."
A spokesman for the Birmingham University Hospitals NHS Foundation Trust, told Birmingham Live: "The Trust takes its responsibilities for all its patients very seriously and is always ready to learn from the events to improve the care it provides.
"This includes, after studying the care provided to Freddie, renewed emphasis on the importance of listening to the concerns of parents of young children and the continued awareness of the warning signs of meningitis and sepsis."