WATCH: Teenager pens touching song for his Irish grandmother to raise money for Alzheimer's

Maureen McGuinness was diagnosed with Alzheimer's disease three years ago, and Harry Gardner has seen its effects

Harry Gardner is a 15-year-old boy whose family has been affected by Alzheimer's. 

Gardner's grandfather Owen McGuinness is from Dublin, while his grandmother Maureen hails from Westmeath, and he has always had a close connection with both of them.

However, in recent years, he has seen his family affected by Alzheimer's, as his grandmother was diagnosed with the disease three years ago. 

Speaking to Newstalk, Gardner said that his parents had always looked to protect them from how much of an effect the disease was having, but on a recent visit he was left shocked by its impact on someone he was so close to.

"She looked so drawn and confused and when I said hello to her, it was clear she did not recognise me. She didn't know who I was even though we had such a close relationship."

Speaking to Pat Kenny, he added that "it was the first time I had seen her in a while. I knew she had the disease, but I didn't know how severe it could be."

That experience inspired him to write the song, and after sharing it with friends and family, it has garnered a huge amount of attention in the UK. 

Gardner stated that he was completely overwhelmed by the response, and that it has gotten much bigger than he ever thought it could be, so much so that even Prime Minister David Cameron has taken notice of it. 

"Mum told me when I got home from school that the cabinet office of the Prime Minister had been calling all day [...] and he awarded me the Points of Light award for outstanding individuals who are making a change in the world. I was just completely blown away, I couldn't believe it." 

Proceeds from the song, which you can buy on iTunes or Amazon Music, will go to help raise funds to fight Alzheimer's.

Listen to Harry on The Pat Kenny Show below.