As many of you know, on 10th June this year, our beautiful daughter Eliza was diagnosed with Rett Syndrome, a rare neurological condition which affects every aspect of her life. 

Rett Syndrome is a genetic condition which most often occurs spontaneously, so it can happen in any family at any time. Eliza was a super happy, healthy baby and developed normally until we noticed that she was not reaching her milestones on time - like crawling, sitting up, talking and playing with toys. 

During the following months, she was in and out of hospital with hearing tests, blood tests, MRI scans and hip X-rays to try and find out why she was not weight bearing or saying many words. Finally, genetic tests resulted in her diagnosis after over two years of wondering what was wrong and hoping that she would one day catch up with her friends.

Girls with Rett Syndrome develop normally for around the first year of their lives, after which they begin to lose skills they have learnt. When Eliza was around 14 months, although not standing or walking, she could point, wave, say "bye-bye" and sit up. She has since lost the ability to do all these things and although she has learnt how to knee-walk to get around, she can't climb steps and she can't weight bear without the help of a standing frame (a big metal frame she is strapped into to force her to stand).

Eliza also became unable to use her hands purposefully, so she cannot wave at us, she can't indicate what she wants by pointing, she can't form sign language, she is unable to feed herself with a spoon or fork and is unable to help with basic things like getting dressed or brushing her teeth. She relies on us totally to keep her safe and look after her. She suffers from abnormal breathing patterns and stomach pains, as well as periods of intense anxiety, which are all part of the condition.

Girls with Rett understand and know much more than their bodies allow them to show - it is as if they are unable to make their body do what they want it to, and unable to form the words to communicate. Most of all we would like Eliza to be able to speak, to tell us when she is hungry, thirsty, happy, worried, in pain, and to say "Mummy", "Daddy", "Angus" and "Nina". We would love to hear her voice. 

The day we heard of Eliza's diagnosis, we felt as if all the hope for her future had been taken away from us. Hearing that one of our children had a condition for which there is no treatment and no cure is the hardest thing we have ever faced. Eliza is only three years old, and we don't know what the future will bring - only half of girls with Rett Syndrome ever learn to walk, and many have heart problems, seizures and develop curvature of the spine. 

I haven't run for a while, and don't think I have done a 10k since before Angus was born(!), but have decided to do the Great Scottish Run 10k for Eliza. The charity I am raising money for, Reverse Rett, funds research into finding treatments and a cure for Rett Syndrome. In 2007, Dr Adrian Bird reversed Rett Syndrome in mice in a lab at the University of Edinburgh. Clinical trials in the UK are only a few years away, and a cure is possible in Eliza's lifetime. To find out more about what Reverse Rett are doing, see www.reverserett.org.uk

Rett Syndrome has stolen Eliza's ability to do almost all the things that a three-year-old should be doing - running, jumping, dancing, playing, singing, telling stories - and we need to believe and hope that one day she might be able to do these things, and more, as she gets older. I want to do everything I can to make sure that one day Eliza has the life we dreamed she would have when she was born. She deserves nothing less and we want nothing in this world more.