Twelve-year-old twins, Jamie and Katie Lucas are opposites in almost every way. Katie is Glee mad. She's extremely sociable and loves dance and pantomime.
Jamie is quieter, preferring his Xbox to outdoor sports. He loves Harry Potter and Lego. He's a massive fan of The Walking Dead and he kills at Monopoly.
Typical of most siblings, they bicker, but there is something the twins have shared from birth that bonds them deeply and separates them from their peers.
Both suffer from cystic fibrosis (CF), a serious genetic disease, affecting the lungs and digestive system and making them constantly prone to chest infections and malnutrition.
Twice daily they self-administer a dizzy cocktail of enzymes, vitamins and treatments, a regime which, if not followed, can have serious repercussions for their current good state of health.
In the immaculately kept bungalow they share with parents, Brenda and Gordon on the outskirts of Ballybofey, Co Donegal, Katie graphically explains what it's like having CF, while Jamie groans and buries his head in the armchair.
"Some people will ask you why you are taking all these tablets and you say 'because of the CF' and they will ask what it is and you will just explain it to them.
"I tell them it is sort of like a disease but not a disease you can catch. It is, sort of like, in your lungs. They won't bother you, then.
"But there are some people who will bother me and Jamie. There's boys up there that actually called Jamie 'sick boy'," she said, her eyes flashing with anger.
For this, Katie has the perfect response, announcing proudly that she and her brother would be appearing on television shortly to talk about CF and the Make a Wish Foundation.
The family had a holiday of a lifetime last year when they travelled to Disneyworld after Katie's wish was made possible by the foundation, which provides treats for children living with life-threatening medical conditions.
"They all got jealous. Some of them were saying 'I wish I were you' and I was thinking 'you wouldn't wish you had CF and had to go to Dublin every two months for check-ups and tests'," she said.
Shortly after their birth in Letterkenny General Hospital Jamie was rushed to Our Lady's Children's Hospital, Crumlin, for treatment for a bowel constriction.
It was then that cystic fibrosis was mentioned for the first time.
"Katie was diagnosed a couple of days later. We had heard of CF but we knew little about it. It was a terrible time," he said.
For the next two years, Crumlin Hospital was the family home.
"We stayed there sleeping on the floors. Crumlin is a brilliant hospital and they have done so much for them but the stress levels were just so high all the time. We can still remember how bad it was but luckily the children can't," Brenda said.