Scaling haplospecific antisense oligonucleotides from N-of-1 to broad use in genetic disease populations by diplotyping

SCN2A

Treatment selectively targeting the SCN2A copy carrying the causal variant, chosen according to the patient's genotype

Individualized antisense oligonucleotide therapies benefit in the United States from an accelerated regulatory pathway, but one designed for a single patient at a time, which limits its reach. The authors developed such a therapy for two patients with SCN2A-complex neurodevelopmental disorder carrying gain-of-function or mixed dysfunction variants, with the treatment sparing the normal copy of the gene. After demonstrating safety and efficacy in these two patients, they assessed the applicability of the approach to 21 SCN2A patients using genome sequencing: ten of them (48%) had a compatible genotype. Analysis of 1000 Genomes Project participants shows that a combination of four such therapies would cover 76.2% of subjects, with selection then made through diagnostic genome sequencing.

Synthesis written by Geno'X. For the full original abstract, please refer to the source publication.

The key idea is to prepare in advance a small number of therapies covering most genotypes, instead of designing one per patient: the diagnostic genome, already performed, then directs the choice. Clinical data rest on two patients only, and the announced coverage remains theoretical, validated in cells rather than in patients. The model is transposable to other dominant disorders, provided regulators accept this group-based logic.

Analysis by Dr Thibaut Benquey