Doctors told a mum that her daughter was 'too pretty' to have an extremely rare genetic condition and instead said she was autistic.
But mum Kathryn Adams refused to accept the diagnosis and so carried out painstaking research on the internet to find out what was really wrong with Melissa, now 10.
In the end, she established that her daughter had Angelman syndrome, a genetic disorder which affects just one in 25,000 people.
Kathryn, 48, from Eccleston, Lancashire, knew there was something wrong when Melissa was just 12 months old.
In an interview with Mail Online, she said: "Melissa was crying all the time. She couldn't lie on her tummy, wasn't sitting up and wasn't making any of the babbling noises babies normally make.
"Her head was very flat at the back too and she wouldn't feed or interact with anybody.
"She'd cling to me like a baby monkey. I knew something wasn't right."
After repeated visits to doctors, Melissa was eventually misdiagnosed as having autism when she was two years old.
Kathryn, who is also mum to 13-year-old Jacob, said: "I knew it wasn't autism. They had made me feel incredibly paranoid when they didn't take me seriously and then they just stuck this label on her."
Kathryn then started doing her own research on the internet and when she typed in Melissa's symptoms Angelman syndrome appeared.
The condition affects the nervous system, causing severe physical and intellectual disability.
But when she returned to her the doctor, she still wasn't listened to.
She said: "Even with all the information out in front of them they still didn't think it was Angelman.
"One doctor even told me that Melissa was 'too pretty' to have it, which I found really quite shocking."
Kathryn finally managed to get her daughter a referral to Alder Hey Children's Hospital in Liverpool for a genetics test when she was two years old.
Melissa was finally diagnosed at the age of three with Angelman syndrome and, just a few months later, was also diagnosed with epilepsy.
She has mobility issues which often cause her to stumble as she walks.
Kathryn, who lives with her husband Stephen, 52, said: "I felt a real mixture of emotions when she was finally diagnosed.
"I was relieved that we finally had answers but I was also very upset because I knew Melissa would never grow up to enjoy a normal childhood.
"I knew she would never really get better and that was hard.
"At the same time I was also really angry that it had taken so long for a correct diagnosis and I felt like, if I hadn't persevered, she would have been stuck with the label that she was autistic."
There is currently no treatment for Angelman syndrome, although research into the condition continues.
Kathryn, along with friends and family, has now set up the Melissa Adams Angelman Foundation in a bid to help raise awareness of the condition and raise funds to find a treatment or cure.
Kathryn said: "Melissa is now a very happy girl and she has this excessive laughter which gets us all going.
"But I suspect there are a lot of children who have been misdiagnosed because many doctors have never heard of the syndrome.
"If I hadn't done my own research, we would never be where we are today. I was angry they hadn't listened to me from the start."
For more information or to make a donation visit www.researchangelman.org.uk
More on Parentdish: The boy who can't stop smiling
Suggested For You
Get top stories and blog posts emailed to me each day. Newsletters may offer personalized content or advertisements. Learn more