Pathophysiology and Treatment of Dravet Syndrome

Dravet syndrome is a severe, early-onset epileptic encephalopathy most commonly resulting from de novo loss-of-function mutations in the SCN1A gene, which encodes the Nav1.1 voltage-gated sodium channel. Haploinsufficiency of Nav1.1 leads to impaired excitability of GABAergic interneurons, disrupting inhibitory control across neural networks and precipitating prolonged febrile and afebrile seizures. Over time, recurrent seizures contribute to cognitive decline, ataxia, behavioural comorbidities and elevated risk of sudden unexpected death in epilepsy. Conventional antiepileptic drugs often provide limited relief and some sodium channel blockers may exacerbate symptoms. Recent therapeutic advances have centred on precision approaches, including cannabidiol, stiripentol and other modulators of inhibitory tone, as well as gene-based interventions designed to restore Nav1.1 expression or function. Emerging strategies seek to rebalance excitatory–inhibitory circuits through targeted delivery of SCN1A or upregulation of endogenous gene expression, offering promise for durable disease modification and improved quality of life.

Research from Nature Portfolio

Unexpected efficacy of a novel sodium channel modulator was demonstrated in a knock-in mouse model carrying a pathogenic SCN1A variant. Chronic administration of the unconventional blocker GS967 improved survival and suppressed spontaneous seizures by reducing aberrant firing of excitatory pyramidal neurons, accompanied by secondary normalization of NaV1.6 levels. In a separate study, mice bearing a clinically relevant A1783V SCN1A missense mutation recapitulated the full spectrum of Dravet syndrome features, including high infant mortality, lowered threshold for heat-induced seizures and multifocal interictal discharges. These animals also exhibited cognitive and motor impairments as well as a global increase in cerebral glucose uptake, underscoring the utility of this platform for preclinical evaluation of targeted therapies.

Pathophysiology and Treatment of Dravet Syndrome publication trend

The graph below shows the total number of articles in pathophysiology and treatment of dravet syndrome across all publications each year (not limited to Nature Index journals).

Technical terms

SCN1A: Gene encoding the alpha subunit of the voltage-gated sodium channel Nav1.1.

Nav1.1: A neuronal sodium channel isoform critical for action potential initiation in inhibitory interneurons.

Haploinsufficiency: A condition in which a single functional copy of a gene does not produce enough protein to maintain normal function.

GABAergic interneurons: Inhibitory neurons that release γ-aminobutyric acid (GABA) to regulate excitatory circuits.

Gene therapy: Delivery of genetic material to correct or compensate for defective genes.

CRISPR/dCas9: A genome-editing platform using a catalytically inactive Cas9 fused to transcriptional activators for targeted gene upregulation.

Adeno-associated virus (AAV): A viral vector commonly used for safe and efficient delivery of therapeutic genes to the central nervous system.

References

1. Altered Function of the SCN1A Voltage-gated Sodium Channel Leads to γ-Aminobutyric Acid-ergic (GABAergic) Interneuron Abnormalities*. Journal of Biological Chemistry (2010).
2. Viral vector-mediated expression of NaV1.1, after seizure onset, reduces epilepsy in mice with Dravet syndrome. Journal of Clinical Investigation (2023).
3. Unexpected Efficacy of a Novel Sodium Channel Modulator in Dravet Syndrome. Scientific Reports (2017).
4. Epilepsy and neuropsychiatric comorbidities in mice carrying a recurrent Dravet syndrome SCN1A missense mutation. Scientific Reports (2019).
5. CRISPR/dCas9-based Scn1a gene activation in inhibitory neurons ameliorates epileptic and behavioral phenotypes of Dravet syndrome model mice. Neurobiology of Disease (2020).
6. Cell-Selective Adeno-Associated Virus-Mediated SCN1A Gene Regulation Therapy Rescues Mortality and Seizure Phenotypes in a Dravet Syndrome Mouse Model and Is Well Tolerated in Nonhuman Primates. Human Gene Therapy (2022).