The tell-tale sign that 11-year-old Mahn Singh had type 1 diabetes was all too obvious for his father Harj. 'I suspected he had it because he was suddenly getting up to pee in the night, which is one of the symptoms,' says Harj, 49, a financial adviser from Ealing, West London, who was himself diagnosed with the condition aged 14.

'I had the blood testing kit because I use it every day, so I gave him the fingerprick test — and sure enough it was 21.9, which is very high.

'It was a terrible shock, we didn't want to believe it. My wife Sharon and I lay awake talking about what to do.