On 28 February 2001 my nephew Matthew was born. Initially he seemed perfectly healthy but the next day my Mum phoned me with the devastating news: "There's something wrong with the baby". It’s not a sentence any parent, grandparent, aunt or uncle wants to hear. And then everything changed. Nurses had noticed some blistering on Matthew's skin and tests revealed he had Epidermolysis Bullosa (EB).

EB is a genetic skin condition that causes skin to blister as a result of the slightest friction or trauma – even contact with clothes or shoes can cause blisters to appear. The blisters, which appear all over the body, need to be burst and drained each day then bandaged to lessen the risk of infection. Certain types of EB are fatal in infancy and others severely life-limiting. There's no known cure for EB. It's pretty rare with around 5000 sufferers in the UK.

The diagnosis was devastating – we'd never heard of EB, there were no signs anything was wrong in the pregnancy and it turned out neither my sister, Liz, or her husband, Alan, were carrying the defective gene. Matthew's sister, Laura, two-and-a-half years older than him, was perfectly healthy.

Matthew spent a week at Great Ormond Street Hospital where more tests were done and the exact type of EB confirmed. EB Simplex is arguably the least worse type of EB but it still has a massive impact on Matthew – and the whole family's – life. He spent much of his time as a baby with his hands and feet bandaged, having blisters burst with needles while on a cocktail on drugs and painkillers. Family life was turned upside down as the reality of having a disabled child set in.

During the first few years Liz and Alan couldn't have coped without Debra, a charity which researches treatments for EB, funds specialist nurses, and supports sufferers and their families.

12 years on Matthew appears like any other 12-year-old boy. He likes tennis, football, computer games and girls (although he won't admit it). He's fun, cheeky, entertaining and clever, and he and Laura are my favourite people to hang out with. But if you look closely you can see blisters and scabs on Matthew's skin – although you'll rarely hear him complain.

So, what am I doing? Climbing Mt Kilimanjaro, that's what. In February 2014 on a trip organised by British Military Fitness, with 30 other keen comrades, I'll be aiming for the top of the biggest free-standing mountain in the world. At almost 6,000m altitude sickness is likely to kick in; it's going to be tough, it's going to be cold, it's going to be painful, and I could well end up with a blister or two myself. But it's all in a good cause: the world's best nephew.

Just to make it clear, I'm paying for the trip myself so 100% of the sponsorship money will go to Debra to help people with EB. I’m sure I’ll be digging deep, both mentally and physically, to make it to the summit – all you need to do is dig deep in your pockets.

Thanks, Emma.