Amy Moar may be a little to the smaller side of statuesque, but she has a heart that must be warmer and bigger than most of the adults around her. She’s a beautiful, if undersized 12 year old, her tiny hands more akin to those of four year old and her height in a similar age pattern.

When she sings to His Holiness the Dalai Lama in Edinburgh’s Usher Hall on 3 June, his intuitive love and respect for all sentient life will be blessed with a very special kind of awareness as he, in turn, blesses her.

Amy’s big moment comes about because the co-ordinator of His Holiness’s visit recently met her music teacher, Janet Anderson. When he heard the story of Amy and of the song, he says “it was as clear as day that Amy should sing this at the Usher Hall for His Holiness and the whole audience.”

“Janet woke up with this song in her head one morning,” says Amy. “It’s called the Why of a Miracle and she asked me to sing it for the Dalai Lama, so we’ve been rehearsing a lot. And Phamie will come and play the harp for me when we record it. We’re going to raise money for children in India.

“When Janet was at the orphanage in India, she saw a rat, and she went ‘Oh, mummy, mummy!” and then it wasn’t a rat at all, it was a snake! So she was really scared but it didn’t get her in the end, thank goodness.”

The talented harpist and composer, Phamie Gow, is indeed accompanying Amy for both the recording of a CD which will be sold to raise money for Indian children and for the Usher Hall event.

Amy is also completely blind, with absolutely no functional sight. Most people registered as blind do have some limited vision. Amy has none and never has had. Her visual perception is non-existent. She must define her life in other ways, with other senses. She doesn’t know colours, so can’t learn about the world around her the way most of us do. Vision plays a crucial role in a child’s psychological development.

Perhaps that is why her astonishing gift of music is so vital, for this is a child Beethoven would understand. His deafness, her blindness. They are kindred spirits, and Beethoven too had small hands that could not span the eight notes of an octave. Amy can barely stretch four notes, but she has her own ways of compensating.

Amy suffers from an extremely rare genetic condition, named after the two men who identified it. Saldino-Mainzer Syndrome has three components, though few children have been unfortunate enough to be struck by all three. Amy has. Her family have not been able to find another family anywhere in the world with the same condition. As well as being blind and having the skeletal disorder which is causing her young spine to triple-curve, threatening her mobility, Amy also has the associated renal dysplasia. What most of us understand as kidney failure.

Exactly two years ago, she received a donor kidney. It undoubtedly saved her life but in the process, it almost cost it. The Moars were, of course, thrilled to receive a donor kidney, but that it came from an adult meant there were someone’s lifetime of viruses in it. “When you receive a donor organ, you inherit whatever viruses that person had, and of course a young child won’t have built up immunity against those,” explains Anne Moar. The virus she inherited with the kidney her life depended upon ironically caused a tumour to grow. Initially unable to isolate where the growth was, it came to medical attention only when the little girl’s gut dramatically ruptured as a result of it.

At the Royal Blind School in Craigmillar, Edinburgh, Amy is discovering computers. “Yeah, we’ve got special computers that have a switch called a big mac switch and when you press it a voice comes up and says ’stop scanning’ (American accent!). You can get special cd-roms with special switches and stuff. And we do Home economics, and music, and all sorts of things. It’s good. ICT is my favourite subject.”

The day before we meet, Amy has been to a concert. When we ask her to play something for us, she sits at Janet Anderson’s grand piano, propped up on an extra cushion, and plays Beethoven’s Fur Elise. Nothing extraordinary about that, you may think. It’s a piece many of us learned, but hold on. Amy has never, ever played it before. In fact she has never even heard it until yesterday. She is replicating what she heard, entirely by ear and memory.

No one really knows for sure what’s up ahead. The next big challenge will be the spinal curvature and its impact on Amy’s mobility, potentially even on her capacity to play the piano she loves so much. “Surgery would be very high risk,” says Anne, “but she is nearly adolescent now and together we will work out decisions. We’ve made many for her already, but now she’s coming to an age where she herself will make those decisions. The specialists are very wary of subjecting her to any more surgery, especially after the problems with her kidney - and she will probably need to have another transplant later - but how do you balance up the risks of surgery against the risk of being confined to a wheelchair?”

So the Moars live life to the full. The rare gene that means Amy’s parents weren’t prepared to take the one in four risk of having another child with the same condition means that they are especially devoted to their remarkable daughter.

“We don’t look too much towards the long term,” says Anne. “We live for the moment.”

Maggie Stanfield is an author of immense skill and experience. She writes regularly on a range of different subjects but has a special interest in children’s health. See http://www.writtenwords.co.uk.