Abstracts

Rationale: Infants with Dravet syndrome typically present with a prolonged febrile seizure at around 6 months of age, due to a pathogenic variant in SCN1A. At presentation, parents are faced with a terrifying scenario when their child has a life-threatening seizure, but have no insight into what the future may hold. With greater access to genetic testing, molecular diagnosis of Dravet syndrome is being made within weeks of seizure onset, redefining the child and family’s future. They are left reeling with unanswered questions and unmet needs, and limited expertise available in the community, while their baby is developing normally and has had relatively few seizures.

Methods: Review of patients with Dravet syndrome liaising with the Developmental and Epileptic Encephalopathy (DEE) Clinical Nurse Consultant (CNC) following consultation with a Paediatric Epileptologist between 2020-2022. Comparison of the impact of early diagnosis (≤8 weeks of seizure onset) of Dravet syndrome with later diagnosis. Examination of medical records for treatment given, psychosocial needs and healthcare requirements of families.

Results: Of 12 patients with Dravet syndrome and an SCN1A pathogenic variant seen between 2020 and 2022, 4 patients received an early diagnosis. Across the cohort, SCN1A-Dravet syndrome was confirmed by molecular testing at a mean age of 51 weeks (range, 4 weeks - 4 years). Families were referred to the DEE CNC for assistance managing multimorbidities including sleep, feeding and behavioural issues, fear of seizures, potential drug side effects, navigating health services, and to address the psychological needs of each parent and siblings when focus is on the child with Dravet syndrome.

Seven of 12 patients, all with a late diagnosis, were treated with carbamazepine or oxcarbazepine which caused seizure exacerbation in all. This treatment was ceased in 5/7 patients due to seizure worsening, whilst 2/7 weaned following the late molecular diagnosis of a pathogenic SCN1A variant.

Conclusions: Later molecular diagnosis of SCN1A-Dravet syndrome was associated with incorrect prescribing of antiseizure medication treatment causing seizure exacerbation which can impact development adversely. Therefore, earlier diagnosis informed appropriate Dravet syndrome treatment. Conversely, considerable parental distress was evident from diagnosis.
_x000D_ Families who receive an early diagnosis of Dravet syndrome are suddenly presented with a grave diagnosis in a relatively well infant with huge impact on the child, family, and wider supports. Understanding this diagnosis needs an expert team that manages the many issues likely to arise in a caring and supportive setting. This huge need has been highlighted with the advent of early genetic testing. The DEE CNC works as a part of a DEE multidisciplinary team to support families facing this devastating diagnosis.

Funding: National Health and Medical Research Council of Australia