Our second son Finlay, 10, was born with Williams Syndrome, a rare disorder affecting only 1 in 20,000 births. He has undergone major heart surgery as a baby, has ongoing health issues affecting his day-to-day living and has learning difficulties. 

But he's also the happiest, most fun loving and sociable child we've ever known. He's taught us to laugh when we're feeling down, to dance in a supermarket aisle and to say hello to everyone we meet. 

So I'll be running the London marathon to give back to the charity who have supported us as a family through Finlay's lifelong diagnosis and who work miracles for those with WS by giving us all an extended family, along with expert guidance and support. 

The Williams Syndrome Foundation is a 100% donation charity set up by parents for families living with Williams Syndrome. Without this charity, we might all feel that little more alone on this unique journey.