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Colchester dad running ultramarathon for his two children with rare syndrome

Oscar Munson, aged six from Colchester, and his sister Mary, eight both have rare genetic disorder Rett Syndrome. After Oscar was diagnosed in Sept 2020 thanks to the 100,000 Genomes Project, his sister Mary, who had previously been diagnosed with autism, was also found to have the condition.


Oscar started showing evidence of developmental problems aged two months when he was unable to keep milk down. He now has severe mobility limitations and is non-verbal.


Mary was originally diagnosed with severe autism, but following Oscar’s diagnosis, was also diagnosed with Rett Syndrome, present in around one in 40,000 boys and one in 10,000 girls in the UK. She is also non-verbal and has epilepsy.


Dad Thomas, 38, an engineering manager, mum Madalaine, 34, and brother George, 10, are fundraising for a sensory room in an outhouse, which they estimate will cost around £15,000 to build.


Thomas said: ‘Because Oscar and Mary have a sensory ‘diet’, it’s really important that the experience is right for them. There’s a centre they go to with a sensory room – blacked out with fibre-optic lights – which is incredibly calming for them. We’d really like to replicate that at home.’


Thomas will be running an ultra-marathon – 50km – on Sunday October 16th, starting at The White Hart in Bergholt which has chosen the family to be their charity for 2022. Thomas said: ‘The 50km aligns with the prevalence of Rett Syndrome in children added together – 1 in 40,000 for boys, and 1 in 10,000 for girls.’


‘The ultramarathon is partly about fundraising, but also about awareness raising. It took some time for our children to be diagnosed, and we are concerned that others are still slipping through the net.’


The family has already raised around £5000 through events including Thomas walking up Snowdon carrying 45kg – the weight of Oscar and Mary combined at the time, as well as fundraisers in local pubs and donations from family, friends and supporters.


Thomas added: ‘We are very grateful for how family, friends and the community have got behind us.  We want Mary and Oscar to have the best quality of life they can, and for George to have the most normal childhood possible. Every penny counts and it means a lot to have so many people backing us.’


The family is being supported by children’s charity Tree of Hope which helps families fundraise for children like Mary and Oscar with healthcare needs and provides charity status to benefit from gift aid, corporate support whilst also providing donor reassurance.


Gill Gibb, Tree of Hope CEO said: ‘We’re delighted to be helping the Munson family with their continuing fundraising and wish Thomas the best of luck with his challenge.’


To donate to Mary and Oscar’s fund, visit


For more information about Rett Syndrome, visit

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