"However, amongst the pain, was hope for our younger daughter, Teddi.

"We are extremely privileged that Teddi is the first child to receive this on the NHS and grateful that she has the opportunity to lead a long and hopefully normal life.

Nala (R) also has MLD but it's too late for her to get the same treatment as her sister
Nala (R) also has MLD but it's too late for her to get the same treatment as her sister© N/A

"Without this treatment, we would be facing both our children being taken away."

'Miracle treatment'

Teddi was treated by Royal Manchester Children's Hospital - in collaboration with Manchester's Centre for Genomic Medicine at Saint Mary's Hospital.

Ally feels privileged Teddi is getting the drug but hopes all babies can be screened for MLD in future
Ally feels privileged Teddi is getting the drug but hopes all babies can be screened for MLD in future© N/A

It's the only hospital in the UK to offer treatment, and one of just five European sites to do so.

During treatment, stem cells are removed from the bone marrow or blood circulation. The faulty gene is the corrected with a healthy copy and the cells reinfused.

Amanda Pritchard, NHS England chief executive, called it a "miracle treatment".

She said: "Thanks to advancements in gene therapies, and the commercial ability of the NHS to strike deals for cutting-edge drugs and then deliver them through our phenomenally skilled specialist staff, children born with this condition now have the opportunity to lead normal, healthy lives.

"It means that children like Teddi can do the things that all children should be able to, like going to school and playing with friends."

Around four babies a year are born in England with MLD. Previously, treatment was limited to managing symptoms and supportive care.

In future, Libmeldy will be available to children who have yet to develop symptoms or are in the early stages of the disease.

Ally urged the NHS to start genetic testing of babies so children like Nala can be diagnosed in time.

She said: "We can only hope that one day, a treatment becomes available for all stages of MLD, and we feel strongly that it should be added to the newborn screening test to save more families from having to go through this heartache."