Gene therapy preserves motor and cognitive function in a rare childhood disease

A gene therapy developed after more than 20 years of research has been shown to be capable of modifying the course of a rare and fatal childhood neurodegenerative disease: metachromatic leukodystrophy (MLD). If administered before the onset of symptoms, it allows children to preserve motor and cognitive functions that would otherwise be irretrievably lost in the first years of life.

The study, published in The New England Journal of Medicine and conducted at San Raffaele Hospital in Milan , confirms that this innovative therapy can preserve the ability to walk, speak, and communicate, even in the long term. "The positive effects are maintained over time, as long as it is administered in the presymptomatic phase," emphasize researchers Francesca Fumagalli and Valeria Calbi, lead authors of the study.

The therapy has been approved in the European Union since 2020 and available in Italy since 2022. It is administered in a single infusion after a phase of chemotherapy and involves transplanting the patient's own stem cells, genetically modified to correct the defect that causes the disease.

However, its effectiveness depends on early diagnosis , before symptoms appear. This is where newborn screening plays a crucial role. It is a simple, noninvasive test performed on newborns using a heel sample, and allows for the early detection of treatable genetic diseases.

In Spain, newborn screening is included in the National Health System's portfolio of services and currently includes the detection of more than 20 diseases, including some of metabolic origin. However, metachromatic leukodystrophy is not yet included among the diseases, which limits the possibilities of early diagnosis of children who could benefit from this revolutionary therapy.

Countries such as Italy have already initiated pilot studies to incorporate early detection of MLD in regions such as Tuscany and Lombardy, while Norway is the only country to systematically include it in its newborn screening. In Spain, various patient associations and healthcare professionals have been calling for years for an expansion of the newborn screening panel to include serious but treatable conditions such as this one.