Reacción a "Reactions: Clinical trial tests gene therapy in severely immunodeficient children"

This is excellent work carried out by a team at the forefront of the field. The data provided are robust and, although ten patients may seem very few, in entities as rare as this type of severe combined immunodeficiency (SCID) they are more than correct.  

This work adds another SCID to the group of primary immunodeficiencies that can be treated by gene therapy. This technique, when it works properly as in this case, usually provides similar or even better results than haematopoietic precursor transplantation with less toxicity, as it does not infuse "external" cells into the patient but genetically modifies the patient's own cells.  

An important theme of the study is that almost all of the patients included had been diagnosed by neonatal screening, so gene therapy was applied in patients free of complications of their disease. This point further reinforces the importance of the neonatal screening-gene therapy pairing in the treatment of these and other genetic diseases.

The main limitation of the study is the relatively small number of patients who will benefit from this treatment, because for the remaining SCIDs with different genetic defects, studies with the same characteristics will have to be performed. Similarly, as the authors comment, longer follow-up is needed to determine the benefit of treatment for non-immunological defects in SCID.