28 February 2015
Last updated at 01:39
Sam Evans was diagnosed with Niemann-Pick type C when he was a baby, but many wait much longer
Seven-year-old Sam Evans' siblings know he is different. Four-year-old twins Jack and Ellie proudly tell people he has a "wobbly brain".
It's their way of explaining his unsteadiness on his feet, his co-ordination problems and the fact that he sometimes asks the same question over and over again.
Sam is a smiley, sociable boy who goes to school and has one-to-one teaching support - but his life will become progressively more difficult.
"In a year he may not be able to talk and a year after that he may not be able to walk," his mother Miriam says.
Sam's parents Will and Miriam, who live in Leeds, were told the devastating news that their first-born had a rare, inherited disease called Niemann-Pick type C when he was four months old.
They were also told he was unlikely to live past the age of two.
"It was absolutely horrific. I couldn't say the words without falling apart."
Awful though the diagnosis was, Miriam says many families wait for years and years for a diagnosis - some up to 20 years or more - and this creates its own problems.
Because the disease is the result of two copies of a faulty gene being passed on to a child, any subsequent children have a one in four chance of getting the disease.
Miriam and Will Evans want doctors to be more aware of the symptoms of Niemann-Pick type C
Also, it means people can live for years without treatment or access to any support.
Now a campaign led by the International Niemann-Pick Disease Alliance (INPDA) wants to change all that.
Think Again. Think NP-C aims to cut diagnosis times by helping doctors unfamiliar with the disease to recognise its key signs and symptoms.
Speeding up diagnosis, it says, will help patients and their families manage a particularly horrible disease which can cause a number of wide-ranging symptoms - from progressive physical problems to psychiatric issues and learning difficulties akin to dementia.
And this is precisely what makes it so difficult to diagnose.
The symptoms can also develop at any time from childhood through to adulthood and vary in severity in each individual.
Symptoms of Niemann-Pick type C can include:
- jaundice at or soon after birth
- an enlarged spleen or liver
- difficulty with upward and downward eye movements
- problems with walking and clumsiness
- difficulty in moving limbs
- slurred, irregular speech
- learning difficulties and progressive intellectual decline
- sudden loss of muscle tone which may lead to falls
- tremors accompanying movement and, in some cases, seizures
- swallowing problems
Jim Green, president of INPDA, says there are bound to be more people out there with undiagnosed Niemann-Pick type C.
"Perhaps the biggest cohort are adults, because it's a non-specific condition.
"We've tried to highlight the three key symptoms and we encourage doctors to ask themselves if it could be NP-C."
Sam and his siblings are very close - they accept him for just the way he is
He explains that there are lots of ways that sufferers and their families can be supported.
And although there is no cure for the disease, drugs are available to help stabilise symptoms and delay the progression of the disease.
Both of Jim Green's sons were diagnosed with Niemann-Pick type C after around three years of tests.
His younger son died at 18, and his elder son is now 38 and "doing extremely well", he says, despite the relentlessly progressive nature of the disease.
Not being able to predict how the disease is going to progress is one of the more terrifying aspects of the condition, he admits.
Children who develop neurological symptoms in early childhood are thought to have a more aggressive form of the disease and may not survive to adolescence.
Others can stay free of symptoms for many years.
- Niemann-Pick Type C Disease (NP-C) is a rare, genetically inherited and neurologically progressive, disease
- It causes fatty substances to accumulate in the brain, affecting the central nervous system, and different parts of the body
- The liver and spleen are also affected
- There is a 25% chance of the disease being inherited if both parents are carriers
- Around 86 people are thought to have NP-C in the UK, and 1,000 people around the world
Sam's mum Miriam says one of the most obvious symptoms is an abnormality in eye movements, which affects virtually everyone with the disease.
Sam is quite unsteady on his feet and is being fitted for a helmet
"Sam's eyes don't move around like everyone else's when he's walking about. And if I am talk to him, he can't flick his eyes up to look at me."
This is something called vertical supranuclear gaze palsy which is relatively simple to detect.
At present, it is thought that one in 120,000 people have the disease, but it could be closer to one in 40,000, Miriam says.
"There are definitely more people out there than we know about."
The advantages of picking up these people are numerous. Patients and families can be supported, and researchers can also find out more about the disease.
The trials of three drugs which could be used to treat Niemann-Pick are in the pipeline and could make a difference to many lives.
And the more people with this rare disease who can be enrolled in trials, the more useful the results will be.