The SJD Barcelona Children's Hospital, the only hospital in Spain that uses gene therapy to treat metachromatic leukodystrophy

A gene therapy has been approved since 2020 to treat metachromatic leukodystrophy, a severe, degenerative metabolic disease that primarily affects very young children. However, until now, candidates for treatment had to travel to Milan in Italy because there were no accredited sites in Spain. The SJD Barcelona Children's Hospital recently became accredited as a Spanish reference center for the provision of this treatment.

Metachromatic leukodystrophy is a rare disease that leads to the destruction of white matter in the brain. Children affected by this metabolic disease develop normally during their first few months of life, but then they suffer a significant regression, losing muscle tone and experiencing difficulties walking and eating.

There are currently no treatments to reverse the effects of the disease, but there is a gene therapy that stalls its onset. It involves extracting a blood sample from the patient and, in the laboratory, adding a correct copy of the defective gene that modifies the involved cells, before reinfusing the blood back into the patient. Candidates for this treatment are children under 30 months of age and who have no symptoms of the disease, or children aged between 30 months and seven years old with very mild symptoms, be they motor-related (instability, tremors) or cognitive (mild delays in expression or understanding).

‘The fact that the therapy needs to be given before the child presents the initial symptoms is a significant hurdle’, explains Neurologist and Head of the Congenital Metabolic Diseases Unit, Àngels García Cazorla. ‘At present, there is no generalised neonatal screening program for the disease and it is difficult to diagnose these children early. That is why the main candidates for the treatment are the siblings of children who have already been diagnosed’, notes Cazorla.

Staff training

To provide staff with the tools they need to identify these patients and facilitate early diagnosis, the SJD Barcelona Children's Hospital has organised a workshop on metachromatic leukodystrophy for staff members and patient associations. This workshop has been promoted by the Congenital Metabolic Diseases Unit in the Neurology Department and, specifically, by doctors Alejandra Darling, Maria del Mar O’Callaghan and Àngels García Cazorla.