Individualized antisense oligonucleotide treatment eligibility of patients living with neurodevelopmental diseases.

With advances in genetic diagnostic tools, pathogenic variants in patients with genetic diseases are being identified at an accelerated pace. For a subset of these patients, individualized genetic interventions such as antisense oligonucleotides (ASOs) would address the disease cause. These individualized, or n-of-1, ASOs are currently being clinically applied in dozens of cases but mainly in patients with neurodegenerative diseases. For neurodevelopmental disorders, however, several questions arise: (1) Are they treatable? (2) What is the appropriate time window? (3) Does the treatment effect justify the burden and risks of treatment? In this consensus statement, we argue for the case to consider the development of individualized ASO treatment for individuals living with neurodevelopmental diseases and discuss which aspects need to be taken into consideration.