Son of Sam

It began with a car crash in the US. My eight-year-old son Sam and I were zooming along in my convertible on Washington's equivalent of the M25 when, just ahead, someone span off the road. We were past the scene in a flash; Sam didn't even see it. He looked back when I pointed it out. I think the drivers involved were OK, but we talked about how suddenly life can change. Bad things can happen even when you don't deserve it. Days later, for Sam, it did.

He had been tired for weeks. We had been back to the UK to sort out schools, so we assumed it was jet lag. But that didn't explain his thirst - an amazing, prodigious thirst that would have him gasping for water morning, noon and night. With the thirst came the need to urinate - and at night a bed-wetting that we hadn't seen for years.

I knew nothing. Still don't, really. History's my thing. I would have just kept ploughing on. But my wife Sarah, a biochemist, knew something was up. Sam and I were oblivious, Sarah was already in private grief.

Three days before Christmas - after a doctor's appointment and a lot of waiting - the verdict was delivered in a room with a rather nice view of the car park. I wasn't even there - I had rushed home to talk to the Radio 4 news desk, thinking this was the same life we had always had, where everything would be fine in the end.I had never heard of type-one diabetes, but by that evening it was part of my life, part of Sarah's, part of Sam's, and part of his twin sister Martha's and five-year-old Clara's, and it will never leave. Sam's pancreas had packed up. For some reason - nobody knows why - his own body was attacking it and would not let it work. Insulin from the pancreas allows us to break down sugars from food into energy. If the body doesn't do it, you die. Sam was dying.