The mum of a nine-year-old has appealed to the new Minister for Health to let her little girl have the only drug that can help her.
Vimizim, which has passed all clinical trials, would cost the exchequer around €400,000 to treat one adult each year.
Grace Cogan's mother, Grainne, is now pleading with those who will decide on approving the drug for use in Ireland: "Don't just look at the cost."
Grace is one of just five children in Ireland with Morquio syndrome, a disease which has severely impaired her growth.
"She is really the size of a two or three-year-old and will probably not grow any any further," Grainne said.
The drug is available in England, Scotland and Wales and one man in Northern Ireland is taking it because he took part in the clinical trials that began four years ago.
Grace lives in county Monaghan near Carrickmacross and loves school, but sometimes has to use her wheelchair because she does not have the energy of her classmates.
She has had two high-risk surgeries to relieve pressure on her spinal cord and Grainne fears that she could face respiratory problems in the future if she does not get access to Vimizim.
The drug would slow down the progress of the disease and give her more energy and a much better quality of life.
"It is not her fault that she has this condition. It is not her fault that the drug is as expensive as it is," said Grainne.
"Grace is a normal nine-year-old girl and she deserves the best chance at life. If there is something out there that helps somebody then they should get it."
Grainne has started the Campaign for Grace on Facebook to highlight her daughter's plight.
"I want Health Minister Simon Harris or whoever makes these decisions, to do their job and make sure this drug is accessible for the children who need it," Grainne said.
"This is a good drug, it is used in other European countries and in Ireland we should have the same access to it. Children should not be discriminated against, they should not have to fight for something that is going to give them a better quality of life. I will not stop my fight until she gets the drug."
In a statement, the HSE said it has received an application for pricing and reimbursement of Elosulfase alfa (Vimizim) from the manufacturer Biomarin.
"As part of the standard processes (agreed with the pharmaceutical industry) around new medicines the HSE commissioned a health technology assessment (HTA) of Elosulfase alfa (Vimizim).
"The HSE is awaiting the submission of the HTA dossier by Biomarin, the manufacturer of the product. Once submitted the dossier would be assessed by the National Centre for Pharmacoeconomics.
"The HTA dossier is an essential component of the assessment process around new medicines and is required to assist the HSE in arriving at an appropriate decision."
The HSE said it cannot comment on the potential outcomes in advance of the assessment process. Elosulfase alfa dose is weight dependent so the cost per patient would vary.