Patient profile, management, and quality of life associated with Dravet syndrome: a cross-sectional, multicentre study of 80 patients in Spain

Perioperative considerations for adult patients with Dravet syndrome in regional centres

Dravet syndrome (DS) is a rare and intractable severe form of epilepsy presenting in infancy with frequent prolonged myoclonic seizures and neurodevelopmental impairment, associated with a SCN1A gene mutation. Seizures are often triggered by temperature fluctuations and hyperthermia. This report presents a woman in her late adolescence with DS complicated with intractable catamenial epilepsy, a sex-specific form of epilepsy with seizure activity prominent during phases of the menstrual cycle. The patient underwent general anaesthesia for a hysteroscopy, cervical dilatation and endometrial curettage with Mirena insertion to improve seizure control. Her perioperative care was optimised for seizure prevention with continuation of antiepileptic medications, strict temperature monitoring and control, optimised anaesthetic agents encompassing induction with propofol and fentanyl with maintenance sevoflurane, followed by attentive postoperative care and monitoring. This case demonstrates that general anaesthesia can safely be delivered to adult patients with DS in rural and regional areas with thorough perioperative planning.

Identification of five novel SCN1A variants

Background

Epilepsy is characterized by recurrent unprovoked seizures. Mutations in the voltage-gated sodium channel alpha subunit 1 (SCN1A) gene are the main monogenic cause of epilepsy. Type and location of variants make a huge difference in the severity of SCN1A disorder, ranging from the mild phenotype (genetic epilepsy with febrile seizures plus, GEFS+) to the severe phenotype (developmental and epileptic encephalopathies, DEEs). Dravet Syndrome (DS) is an infantile-onset DEE, characterized by drug-resistant epilepsy and temperature sensitivity or febrile seizures. Genetic test results reveal SCN1A variants are positive in 80% DS patients and DS is mainly caused by de novo variants.

Methods

Trio-whole exome sequencing (WES) was used to detect variants which were associated with clinical phenotype of five probands with epilepsy or twitching. Then, Sanger sequencing was performed to validate the five novel SCN1A variants and segregation analysis. After analyzing the location of five SCN1A variants, the pathogenic potential was assessed.

Results

In this study, we identified five novel SCN1A variants (c.4224G > C, c.3744_3752del, c.209del, c.5727_5734delTTTAAAACinsCTTAAAAAG and c.5776delT) as the causative variants. In the five novel SCN1A variants, four were de novo and the remaining one was inherited. All novel variants would be classified as "pathogenic" or "likely pathogenic."

Conclusion

The five novel SCN1A variants will enrich the SCN1A mutations database and provide the corresponding reference data for the further genetic counseling.