To define the phenotypic and mutational spectrum of epilepsies related to DEPDC5, NPRL2 and NPRL3 genes encoding the GATOR1 complex, a negative regulator of the mTORC1 pathway We analyzed clinical and genetic data of 73 novel probands (familial and sporadic) with epilepsy-related variants in GATOR1-encoding genes and proposed new guidelines for clinical interpretation of GATOR1 variants. The GATOR1 seizure phenotype consisted mostly in focal seizures (e.g., hypermotor or frontal lobe seizures in 50%), with a mean age at onset of 4.4 years, often sleep-related and drug-resistant (54%), and associated with focal cortical dysplasia (20%). Infantile spasms were reported in 10% of the probands. Sudden unexpected death in epilepsy (SUDEP) occurred in 10% of the families. Novel classification framework of all 140 epilepsy-related GATOR1 variants (including the variants of this study) revealed that 68% are loss-of-function pathogenic, 14% are likely pathogenic, 15% are variants of uncertain significance and 3% are likely benign. Our data emphasize the increasingly important role of GATOR1 genes in the pathogenesis of focal epilepsies (>180 probands to date). The GATOR1 phenotypic spectrum ranges from sporadic early-onset epilepsies with cognitive impairment comorbidities to familial focal epilepsies, and SUDEP.

Objective: Ketogenic diet therapy (KDT) is a group of high‐fat, low‐carbohydrate diets used as an effective treatment option for children and adults with drug‐resistant epilepsy. There is limited research on the efficacy of KDT in infants, where there is the highest incidence of onset of the epilepsy. We aimed to systematically review studies that have reported on response to KDT in infants with epilepsy.Methods: An online comprehensive literature search was performed, including studies that provided seizure frequency data for at least one infant younger than 2 years of age who was treated with KDT for ≥1 month. The proportions of infants achieving ≥50% seizure reduction, seizure‐freedom rates, retention rates, and reported side effects were extracted from studies. Meta‐analyses were performed using a random‐effects model, and subgroup analyses were performed to investigate possible between‐study heterogeneity.Results: Thirty‐three studies met inclusion criteria and were included in the final analysis, with a total of 534 infants with efficacy data. Two studies were randomized‐controlled trials, and the remainder were uncontrolled cohort studies. All studies were categorized as low quality. Meta‐analyses of uncontrolled studies estimate 59% (95% confidence interval [CI] 53‐65) of infants achieved ≥50% seizure reduction and 33% (95% CI 26‐43) of infants achieved seizure freedom. Retention rates ranged from 84% at 3 months to 27% at 24 months. The most commonly reported side effects were dyslipidemia (20/171, 12%), vomiting (11/171, 6%), constipation (7/171, 4%), gastroesophageal reflux (6/171, 4%), and diarrhea (6/171, 4%).Significance: This review indicates that KDT is safe and tolerable and that it can be an effective treatment option for infants with drug‐resistant epilepsy. However, there are few studies focusing on infants treated with KDT, and high‐quality evidence is lacking. High‐quality randomized‐controlled trials are needed to confirm the effectiveness, safety, and tolerability of dietary treatment in this vulnerable age group.

Sudden unexpected death in epilepsy (SUDEP) represents the most severe degree of the spectrum of epilepsy severity and is the commonest cause of epilepsy-related premature mortality. The precise pathophysiology and the genetic architecture of SUDEP remain elusive. Aiming to elucidate the genetic basis of SUDEP, we analysed rare, protein-changing variants from whole-exome sequences of 18 people who died of SUDEP, 87 living people with epilepsy and 1479 non-epilepsy disease controls. Association analysis revealed a significantly increased genome-wide polygenic burden per individual in the SUDEP cohort when compared to epilepsy (P = 5.7 × 10(- 3)) and non-epilepsy disease controls (P = 1.2 × 10(- 3)). The polygenic burden was driven both by the number of variants per individual, and over-representation of variants likely to be deleterious in the SUDEP cohort. As determined by this study, more than a thousand genes contribute to the observed polygenic burden within the framework of this study. Subsequent gene-based association analysis revealed five possible candidate genes significantly associated with SUDEP or epilepsy, but no one single gene emerges as common to the SUDEP cases. Our findings provide further evidence for a genetic susceptibility to SUDEP, and suggest an extensive polygenic contribution to SUDEP causation. Thus, an overall increased burden of deleterious variants in a highly polygenic background might be important in rendering a given individual more susceptible to SUDEP. Our findings suggest that exome sequencing in people with epilepsy might eventually contribute to generating SUDEP risk estimates, promoting stratified medicine in epilepsy, with the eventual aim of reducing an individual patient's risk of SUDEP.

Ketogenic dietary therapies are an effective treatment option for children with drug-resistant epilepsy. There is an increasing worldwide interest in using these diets to manage adult epilepsy; uncontrolled studies show similar response rates to those in children. Despite this, there are only a few centres with dedicated services for adults. We clearly need controlled studies of this treatment in adults. Here, we aim to familiarise adult neurologists with the evidence base for these diets and give practical advice on starting and maintaining them in adults.

This prospective open-label feasibility study aimed to evaluate acceptability, tolerability and compliance with dietary intervention with K.Vita, a medical food containing a unique ratio of decanoic acid to octanoic acid, in individuals with drug-resistant epilepsy. Adults and children aged 3–18 years with drug-resistant epilepsy took K.Vita daily whilst limiting high-refined sugar food and beverages. K.Vita was introduced incrementally with the aim of achieving ≤35% energy requirements for children or 240 ml for adults. Primary outcome measures were assessed by study completion, participant diary, acceptability questionnaire and K.Vita intake. Reduction in seizures or paroxysmal events was a secondary outcome. 23/35 (66%) children and 18/26 (69%) adults completed the study; completion rates were higher when K.Vita was introduced more gradually. Gastrointestinal disturbances were the primary reason for discontinuation, but symptoms were similar to those reported from ketogenic diets and incidence decreased over time. At least three-quarters of participants/caregivers reported favourably on sensory attributes of K.Vita, such as taste, texture and appearance, and ease of use. Adults achieved a median intake of 240 ml K.Vita, and children 120 ml (19% daily energy). Three children and one adult had ß-hydroxybutyrate >1 mmol/l. There was 50% (95% CI 39–61%) reduction in mean frequency of seizures/events. Reduction in seizures or paroxysmal events correlated significantly with blood concentrations of medium chain fatty acids (C10 and C8) but not ß-hydroxybutyrate. K.Vita was well accepted and tolerated. Side effects were mild and resolved with dietetic support. Individuals who completed the study complied with K.Vita and additional dietary modifications. Dietary intervention had a beneficial effect on frequency of seizures or paroxysmal events, despite absent or very low levels of ketosis. We suggest that K.Vita may be valuable to those with drug-resistant epilepsy, particularly those who cannot tolerate or do not have access to ketogenic diets, and may allow for more liberal dietary intake compared to ketogenic diets, with mechanisms of action perhaps unrelated to ketosis. Further studies of effectiveness of K.Vita are warranted.