At just nine days old, Samuel is the youngest child in North America to have received Zolgensma, a gene therapy for the treatment of spinal muscular atrophy (SMA). Thanks to this achievement from the Montreal Children's Hospital (MCH), his quality of life will be greatly improved.

SMA is a rare progressive genetic disease affecting one in 10,000 people. It has an effect on nerve cells in the spinal cord and brain stem, limiting the ability to walk, eat and, eventually, breathe. The life expectancy of people affected is generally limited.

Zolgensma can stop the progression of the disease. The earlier it is administered, the better the results. Now at nearly four months old, Samuel's development is completely normal.

An interdisciplinary approach

Samuel's older sister Ariane also has SMA. As soon as their mother became pregnant with Samuel, she underwent tests, which revealed that the unborn child was affected. The team at the Montreal Children's Hospital was able to quickly put a plan in place.

" It was truly a team effort that enabled us to treat Samuel so early. I had the opportunity to monitor the baby's condition throughout the pregnancy with an obstetrician from the McGill University Health Centre. The MCH Neonatal Intensive Care Unit ensured that he was well during and after the birth, and we continue to monitor his progress closely with the Complex Care Services and his physiotherapist. What's more, we were able to orchestrate the rapid shipment of antibodies to the virus that carries the treatment (AAV9) thanks to the MCH laboratory and the pharmacy gave the go-ahead for their administration on a Saturday to avoid losing precious days," explains Dr. Maryam Oskoui, Head of Pediatric Neurology at the MCH, who coordinated the action plan.

She was the one who administered the intravenous treatment to Samuel last spring.

Earlier is better

During SMA Awareness Month, held in August, Dr. Oskoui stresses the importance of early detection of the disease.

"Ariane was the second person in the world to receive Zolgensma at the start of clinical trials on this drug. Because it was the first tests on humans, the dose was lower. She was six months old at the time. Now eight years old,  Ariane needs permanent tracheostomy ventilation and moves very little," she points out.

Zolgensma has been reimbursed by the Régie de l'assurance maladie du Québec since October 2021. In June 2022, the Ministère de la Santé et des Services sociaux announced that SMA screening would soon be added to the Programme québécois néonatal de dépistage sanguin et urinaire.

"We have a bittersweet feeling, as Ariane was born just a little too early to have access to timely treatment. But we're very grateful that Samuel benefited so quickly, and relieved that a whole generation of children with SMA will have it too. No other family will ever have to go through these difficult times again," says Audrey Bouchard, mother of Samuel, Ariane and another five-year-old boy who does not have the disease.

She would like to thank the MCH team, her "hospital family". "They organized themselves, explained what they were going to do and what was going to happen. We felt supported and listened to," she says.

The importance of addressing rare diseases

Rare diseases are individually rare, but collectively they affect around three million people in Canada and 500,000 in Quebec. Like spinal muscular atrophy, they are often progressive, most often affect children, have limited or no treatment options, and require complex medical and personal care. It is therefore essential to better understand rare diseases and develop new therapies, and spinal muscular atrophy is no exception.

The McGill University Health Centre, recently recognized as a Centre de référence interdisciplinaire pour les soins et la recherche en maladies rares, is proud of the variety and high quality of the expertise it brings together in this field, whether in diagnosis, care or basic and clinical research. It is also grateful to the public, private and philanthropic organizations that make these activities possible, for the benefit of sick children and adults.