It's known as the most expensive drug in the world, costing €2m for a single dose. It's used to treat a rare genetic neuromuscular condition called spinal muscular atrophy (SMA) type 1. It's called Zolgensma and Karen Vickers told Ray D'Arcy on Wednesday that her 8 month old daughter Livie, who has SMA, needs the drug to ensure her quality of life, if not her very survival. Ray wanted to know when Karen and her partner Keith first noticed that something was not quite right in baby Livie's development.

"It was probably around four and a half months. So, like, typically a baby of that age would start to roll and lift their head up and, like, Livie was kind of slightly lifting her head up, but never fully lifting the head up."

Although healthcare workers told Karen to give Livie time to reach her milestones, it became apparent soon enough that it was getting harder for Livie to do things like lifting her head, rather than easier. When eventually Livie was seen by the staff at Crumlin Children's Hospital, where they got a diagnosis within the hour. Karen and Keith were – like most of us – completely unaware of SMA.

"Even in our worst nightmares we couldn't imagine this and we never even heard of it. Even when they were calling out the diagnosis, like, we just, oh, like, devastation."

The hardest thing about the condition, Karen told Ray, is the huge amount of uncertainty, as every child can have different symptoms and the future becomes very unclear. Before the advent of an earlier drug, Spinraza, a diagnosis of SMA almost always meant an infant would not survive beyond its second birthday. Spinraza aims to slow the progression of SMA, but Zolgensma is different, as Karen explained:

"It's a once-off treatment. It's – I think it's done through a lumbar puncture and it's once-off, so if Livie got the treatment, she wouldn't need anything done again."

SMA leads to a decrease in SMN protein, which is necessary for the survival of motor neurons and this decrease means that muscles weaken over time. Treatment with Zolgensma leads to an increase in SMN protein, which in turn should lead to improved muscle function. Some of the results from trials of the drug in the US have been very exciting for Karen:

"Some of the mothers that have had their children treated with the Zolgensma have seen incredible results, like children reaching their motor milestones, which we didn't think was possible."

Karen and Keith have set up a GoFundMe page to try to raise the huge amount required to get Livie the treatment she so desperately needs. And time is not on their side.

"With the treatment in the States, it's available up to the age of 2 years. And also because Livie's condition is very progressive, so the muscles will continue to get weaker… So you really are kind of fighting the clock, basically."

You can donate to the fund here. And you can hear Karen's entire conversation with Ray here.

Niall Ó Sioradáin