Doctors at first thought the tiny lump in Emma Evans' neck was merely swollen glands.
Within months however they had the shocking diagnosis that not only had Emma got a potentially serious illness of the nervous system, but that at least four other members of her close family also had the same condition, neurofibromatosis.
Neurofibromatosis 1 (NF1) occurs in one in 2,500 births and mainly affects the nervous system and the skin.
The hallmark is the development of neurofibroma - benign tumours that form on nerve coverings on or under the skin.
But the condition is unpredictable and as yet incurable. It can range from unusual skin pigmentation, or cafe au lait spots to serious and disfiguring tumours, which can sometimes turn malignant.
"When we first got the diagnosis it was like a bombshell and we were devastated," said Tracey, from Surrey.
"After speaking with the doctors it became clear both myself and my son also have mild forms of the condition.
"I had always presumed the light brown birth marks on my skin, which are characteristic of NF1, were just freckles.
"It was all from Emma being diagnosed."
Tracey later discovered that her mother and sister also had mild forms of NF1.
"When I was young my mum had a few lumps removed, basically because she was irritated by their appearance, it was cosmetic mainly - but these tumours can turn nasty."
The condition is not well known, but consultant neurologist Dr Rosalie Ferner, says it perhaps should be.
"The incidence is about the same as cystic fibrosis, but no one knows about it."
It is not just among the public that NF1 is a mystery. Dr Ferner said many non-specialist medics were also unclear about the condition and its effects.
Now two hospitals - Guy's and St Thomas' London, where Dr Ferner works and the Central Manchester University Hospitals NHS Foundation Trust have been made centres of excellence for the condition, in a bid to improve diagnosis, treatment and knowledge.
It will mean specialist doctors, ophthalmologists, nurses, psychiatrists and paediatricians being together under the same roof.
The complications of NF1 can be wide ranging and involve many of the body systems.
They include benign and malignant tumours, speech problems, abnormalities of bone, learning difficulties and high blood pressure.
Some problems associated with NF1 are complex, rare, difficult to diagnose and treat and can be life-threatening.
Until recently it was wrongly assumed that the Elephant Man Joseph Merrick suffered from neurofibromatosis.
An imaging study, however, showed his problems were due to tissue and bone overgrowth due to a rare condition called Proteus Syndrome.
Dr Ferner said: "NF1 is a genetic condition and sufferers can get benign and malignant tumours which makes it distressing.
"Also if you have a condition with multiple lumps it makes it difficult to decide which might be a problem.
"Even if they are benign they can be a problem from a cosmetic point of view - people get stared at in the street and bullied.
"The condition is very variable which means that if you have a member of the family who has it very badly it does not automatically mean that if you inherit it - and you have a one in two chance - that yours will be as severe.
"But living with unpredictably is a major problem and you never know what problem you are going to get because it can affect the brain, or the heart, the spine, the peripheral nerves or the bones."
When to operate
Emma's neck lump is thought to be benign, but Dr Ferner said the positioning on her neck made it worrying.
"As Emma gets older the tumour grows with her. It is in a position that might affect the nerves for swallowing and breathing passages.
"As we think it is benign we have to weigh up leaving it or deciding the right time and balancing the problems of surgery with an active young lady having problems swallowing and breathing. It is a fine balance."
Her mother agreed: "It is a real 'Catch 22', as they don't want it to affect her speech or nerves.
"Dr Ferner said they would not operate until it was life-threatening."
Each year Emma, now aged 12, goes for an MRI scan (Magnetic Resonance Imaging) to check how much the lump has grown.
She also needs regular ophthalmology appointment to check for tumours behind the eye.
"The lump has not affected Emma and she is happy and giggly," said Tracey.
"It measures 6cm by 3-4cm - but it is growing.
"It usually grows at a steady pace. If you get pins or needles, sudden numbness, movement or bladder problems you need to go to the doctor because they indicate problems."