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The short version

  • Two teenagers with distinct SCN2A gene mutations received tailored antisense oligonucleotide treatments that drastically reduced seizure frequency.
  • One patient, previously unable to walk independently, regained the ability to take steps unassisted after more than a year of spinal injections.
  • While results are encouraging, researchers caution that these individual cases do not yet prove the broader efficacy or safety of n-of-one medicine.

A new class of personalized medicine has demonstrated significant potential in treating severe childhood epilepsy caused by rare genetic mutations. Research published in Nature Medicine details two parallel clinical trials involving teenagers who received custom-designed drugs targeting their specific DNA errors. The findings highlight a shift toward n-of-one therapies, where treatments are engineered for individual patients rather than large groups, offering hope for conditions previously deemed untreatable due to their rarity.

Connor Dalby, now 17, experienced up to one hundred seizures daily as an infant and was not expected to survive past age four. After receiving spinal injections of a custom antisense oligonucleotide over more than a year, his seizure frequency dropped by approximately ninety percent. More remarkably, Dalby has regained the ability to walk independently, taking fifty to sixty steps without assistance. His mother noted that this improvement has fundamentally altered their family’s quality of life and granted him new levels of independence.

News Journal

The second participant, a nine-year-old boy with a different mutation in the same SCN2A gene, also showed positive outcomes. Although his seizure reduction of twenty-six percent was not statistically significant, he was able to discontinue a medication he had relied on since infancy. Both patients tolerated the treatments well, with no serious adverse events or abnormal results in laboratory and brain analyses. The drugs work by binding to genetic messengers associated with harmful gene copies, preventing them from producing faulty proteins while allowing healthy copies to function normally.

Researchers emphasize that these results suggest neurological damage once thought irreversible may be reversible, indicating continued brain plasticity even after critical developmental windows. However, the benefits are not permanent; because the treatments do not alter DNA, patients require repeated spinal injections to maintain improvements. Experts caution that while the moral imperative to treat rare conditions is strong, two cases are insufficient to establish the broader safety and efficacy of this approach for other patients.

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Go to the original reporting

  • Smithsonian Magazine↗After Receiving a Custom Experimental Medicine, a Teen With a Rare Genetic Disorder Walked on His Own for the First Time