(NewsNation) — The FDA has approved the first gene therapy for metachromatic leukodystrophy (MLD), a rare and fatal disease primarily affecting children under the age of seven.

The staggering price tag of $4.25 million makes Lenmeldy the world’s most expensive drug.

Kendra Riley is a mother of three girls, two of whom — Olivia and Keira — were diagnosed with MLD. While Keira was fortunate to receive the gene therapy in Italy before showing symptoms, it was too late for Olivia, who is currently in hospice care.

“Since Keira received the therapy, she has shown absolutely zero symptoms. It’s honestly been a miracle,” Riley said during a Saturday interview on “NewsNation Prime.”

MLD is a progressive disease that attacks the nervous system, leading to symptoms such as loss of sensation, mobility, and speech. The approval of Lenmeldy marks a significant milestone in the medical world, offering the potential to halt or slow the progression of MLD with a single treatment.

Because the treatment was not available in the U.S. at the time of Keira’s diagnosis, the family made a dramatic move and went to Italy in 2020 to access treatment, making Keira the 32nd child in the world to receive this therapy.

“We’re parents. We will do absolutely anything for our children … We had one month’s time to raise enough money to move to Italy and make sure she could live a normal life,” Riley said.

Riley’s advocacy for families facing similar challenges resonates deeply. She emphasizes the importance of ensuring that no family has to endure the heartache of losing a child to MLD when life-saving treatment exists. Despite the emotional toll, Riley remains resilient, advocating for affordable access to the therapy.

“Consider the millions of dollars you’re already putting in to keeping these children alive by the age of six. I think it would be a no brainer to spend the same amount on saving a child’s life and saving a family,” Riley said to insurance companies.