Race against time for young siblings with ultra-rare condition affecting just 70 people worldwide

• Tap above to watch video report by Rags Martel

Two young siblings are in a race against time after being diagnosed with an ultra-rare condition thought to affect just 70 people worldwide.

Tom Dixon, 15, and Rosie Dixon, nine, were both diagnosed with a DHDDS gene mutation.

The condition can cause children to experience developmental delays and seizures including tremors, co-ordination issues and learning difficulties and potentially lead to Parkinsonism.

Tom and Rosie's parents from East Sheen are helping fund research and after raising £15,000 in a charity walk, dad Charlie will cycle nearly 1,000 miles on a tandem bike from John O'Groats to Land's End wearing a lab coat.

Speaking to ITV News London Charlie said: "It's a the reflection of the work scientists are doing. In terms of research it's a pretty difficult environment to work in in terms of ultra rare research.

"They're really struggling for funding. So we're really grateful for the efforts they're all making to try and find a treatment."

Mum Mel Dixon added: "The dream is to get a treatment. A win for us would be that we can halt disease progression in children and other patients and hopefully see some improvements as well.

"But then the hope for the next generation is they might not have any of the symptoms."

When Tom and Rosie were diagnosed with DHDDS there were only 59 confirmed cases in the world, increasing to 70 now.

The diagnosis came after Charlie and Mel couple noticed their two children were late with key milestones such as walking and speaking.

Both were diagnosed with mild learning difficulties and dyspraxia – which affects movement and co-ordination – while at primary school, and Tom was later diagnosed with autism.

After Tom and Rosie were offered whole genome sequencing testing at St George’s Hospital - which detects changes in genetic make-up - the DHDDS gene mutation was discovered.

Charlie will start his cycle ride in John O’Groats on August 30 and cycle, against the wind, in lab coats through the Scottish Highlands, Lake District, Welsh Borders and Dartmoor, staying at bed & breakfasts along the way, before arriving in Land’s End on September 8 where he will be “in need of a beer”.

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