De Novo Truncating Variants in the Last Exon of SEMA6B Cause Progressive Myoclonic Epilepsy.

De novo variants (DNVs) cause many genetic diseases. When DNVs are examined in the whole coding regions of genes in next-generation sequencing analyses, pathogenic DNVs often cluster in a specific region. One such region is the last exon and the last 50 bp of the penultimate exon, where truncating DNVs cause escape from nonsense-mediated mRNA decay [NMD(-) region]. Such variants can have dominant-negative or gain-of-function effects. Here, we first developed a resource of rates of truncating DNVs in NMD(-) regions under the null model of DNVs. Utilizing this resource, we performed enrichment analysis of truncating DNVs in NMD(-) regions in 346 developmental and epileptic encephalopathy (DEE) trios. We observed statistically significant enrichment of truncating DNVs in semaphorin 6B (SEMA6B) (p value: 2.8 × 10-8; exome-wide threshold: 2.5 × 10-6). The initial analysis of the 346 individuals and additional screening of 1,406 and 4,293 independent individuals affected by DEE and developmental disorders collectively identified four truncating DNVs in the SEMA6B NMD(-) region in five individuals who came from unrelated families (p value: 1.9 × 10-13) and consistently showed progressive myoclonic epilepsy. RNA analysis of lymphoblastoid cells established from an affected individual showed that the mutant allele escaped NMD, indicating stable production of the truncated protein. Importantly, heterozygous truncating variants in the NMD(+) region of SEMA6B are observed in general populations, and SEMA6B is most likely loss-of-function tolerant. Zebrafish expressing truncating variants in the NMD(-) region of SEMA6B orthologs displayed defective development of brain neurons and enhanced pentylenetetrazole-induced seizure behavior. In summary, we show that truncating DNVs in the final exon of SEMA6B cause progressive myoclonic epilepsy.

Glycemic biomarkers in children with drug-resistant epilepsy on various types of ketogenic diet therapies: A cross-sectional study.

OBJECTIVE: This study was undertaken to determine the hemoglobin A1c (HbA1c) and modified glucose-ketone index (mGKI) in children on different types of ketogenic diet (KD) for treatment of drug-resistant epilepsy, with attempts to evaluate their relationships with components of diet regime and other biomarkers. METHODS: We conducted a cross-sectional study in children with drug resistant epilepsy aged between 6 months and 18 years, who were on various types of KD therapies without any change in regime for at least 3 months. Parental interview, review of medical records, and a single measurement for blood ketone, HbA1c, and plasma carnitine were performed. mGKI was the ratio of an average plasma glucose estimated from HbA1c to blood ß-hydroxybutyrate level. RESULTS: Thirty-four patients were recruited with a median blood ketone of 2.90 mmol·L-1 and median HbA1c of 4.55%. Those on classical KD (cKD) had higher blood ketone (p = .031) and lower HbA1c (p = .010) and mGKI (p = .021) than those receiving modified Atkins diet, although both shared similar percentages of calories from carbohydrate (p = .211). The cKD and medium-chain triglyceride (MCT) KD groups had similar HbA1c (p = .252) and mGKI (p = .510). Blood ketone (p = .045) and the percentage of calories from MCT (p = .037) were the two main independent variables, inversely correlating with HbA1c. Other than plasma acylcarnitine (p = .047), neither blood ketone (p = .188) nor HbA1c (p = .170) could predict seizure reduction reliably. Both plasma acylcarnitine ≥ 6 µmol·L-1 (p = .013) and mGKI ≤ 2.2 (p = .013) were significantly associated with good seizure control. SIGNIFICANCE: HbA1c could potentially be useful for monitoring KD adherence or, indirectly, systemic ketosis in nondiabetic children on KD for drug-resistant epilepsy. Plasma acylcarnitine and mGKI could be important biomarkers in the management of KD therapy.

Vitamin D deficiency and its risk factors in Malaysian children with epilepsy.

OBJECTIVE: Long-term use of antiepileptic drugs (AEDs) is a significant risk factor for vitamin D deficiency in children with epilepsy. The aims of our study were to evaluate the prevalence and risk factors for vitamin D deficiency among Malaysian children with epilepsy. METHODS: Cross-sectional study of ambulant children with epilepsy on long-term AEDs for >1 year seen in three tertiary hospitals in Malaysia from April 2014 to April 2015. Detailed assessment of pubertal status, skin pigmentation, sunshine exposure behavior, physical activity, dietary vitamin D and calcium intake, anthropometric measurements and bone health blood tests (vitamin D, alkaline phosphatase, calcium, phosphate, and parathyroid hormone levels) were obtained on all patients. Vitamin D deficiency was defined as 25-hydroxy vitamin D [25(OH)D] levels ≤35 nmol/L and insufficiency as 25(OH)D levels of 36-50 nmol/L. RESULTS: A total of 244 children (146 male) participated in the study. Ages ranged between 3.7 and 18.8 years (mean 12.3 years). 25(OH)D levels ranged between 7.5 and 140.9 nmol/L (mean 53.9 nmol/L). Vitamin D deficiency was identified in 55 patients (22.5%), and a further 48 (19.7%) had vitamin D insufficiency. Multivariate logistic regression analysis identified polytherapy >1 AED (odds ratio [OR] 2.16, 95% confidence interval [CI] 1.07-4.36), age >12 years (OR 4.16, 95% CI 1.13-15.30), Indian ethnicity (OR 6.97, 95% CI 2.48-19.55), sun exposure time 30-60 min/day (OR 2.44, 95% CI 1.05-5.67), sun exposure time <30 min/day (OR 3.83, 95% CI 1.61-9.09), and female (OR 2.61, 95% CI 1.31-5.20) as statistically significant (p < 0.05) risk factors for vitamin D deficiency. SIGNIFICANCE: Despite living in the tropics, a high proportion of Malaysian children with epilepsy are at risk of vitamin D deficiency. Targeted strategies including vitamin D supplementation and lifestyle advice of healthy sunlight exposure behavior should be implemented among children with epilepsy, particularly for those at high risk of having vitamin D deficiency.

Severe and rare neurological manifestations following COVID-19 infection in children: A Malaysian tertiary centre experience.

INTRODUCTION: Since the emergence of COVID-19, we have experienced potent variants and sub-variants of the virus with non-specific neurological manifestations. We observed a surge of the Omicron variant of COVID-19 patients with neurological manifestations where less cases of multisystem inflammatory syndrome in children (MIS-C) were reported. This article describes our experience of children with severe and rare neurological manifestations following COVID-19 infection. METHODS: This is a retrospective observational case series of patients under 18 years old who fulfilled the WHO COVID-19 case definition and were referred to our paediatric neurology unit at Hospital Tunku Azizah Kuala Lumpur. Their demographic data, neurological symptoms, laboratory and supporting investigations, neuroimaging, treatment and outcomes were collected and analysed. RESULTS: There were eleven patients with neurological manifestations who fulfilled the WHO COVID-19 case definition. Nine patients presented with seizures and/or encephalopathy, one patient with eye opsoclonus and another patient with persistent limbs myokymia. Based on the history, clinical, electrophysiological and radiological findings, two of them had febrile infection-related epilepsy syndrome, two had acute disseminated encephalomyelitis, two had acute necrotising encephalopathy of childhood, one each had hemiconvulsion-hemiplegia-epilepsy syndrome, acute encephalopathy with bilateral striatal necrosis, hemi-acute encephalopathy with biphasic seizures and reduced diffusion, infection-associated opsoclonus and myokymia. CONCLUSIONS: This case series highlighted a wide spectrum of neurological manifestations of COVID-19 infection. Early recognition and prompt investigations are important to provide appropriate interventions. It is essential that these investigations should take place in a timely fashion and COVID-19 quarantine period should not hinder the confirmation of various presenting clinical syndromes.

Management of status epilepticus in Malaysia: A national survey of current practice and treatment gap.

INTRODUCTION: Early and effective treatment is fundamental in status epilepticus (SE) management. At the initiative of the Epilepsy Council of Malaysia, this study aimed to determine the treatment gap in SE across different healthcare settings in Malaysia. METHODS: A web-based survey was sent to clinicians involved in the management of SE, across all states and at all levels of healthcare services. RESULTS: A total of 158 responses were received from 104 health facilities, including 23 tertiary government hospitals (95.8% of all government tertiary hospitals in Malaysia), 4 (80.0%) universities, 14 (6.7%) private, 15 (11.5%) district hospitals and 21 clinics. Intravenous (IV) diazepam was available in 14 (93.3%) district and 33 (80.5%) tertiary hospitals for prehospital management. Non-IV benzodiazepine (rectal diazepam and intramuscular midazolam) was not widely available in prehospital services (75.8% and 51.5%). Intramuscular midazolam was underutilised (60.0% in district and 65.9% in tertiary hospitals). IV sodium valproate and levetiracetam were only available in 66.7% and 53.3% of the district hospitals, respectively. Electroencephalogram (EEG) services were available in only 26.7% of the district hospitals. Non-pharmacological therapies such as ketogenic diet, electroconvulsive therapy, and therapeutic hypothermia were not available in most district and tertiary hospitals for refractory and super-refractory SE. CONCLUSIONS: We identified several gaps in the current practice of SE management, including limited availability and underutilization of non-IV midazolam in prehospital services, underutilization of non-IV midazolam and other second-line ASMs, and lack of EEG monitoring in district hospitals and limited treatment options for refractory and super-refractory SE in tertiary hospitals.

Geniospasm: A systematic review on natural history, prognosis, and treatment.

BACKGROUND: Geniospasm is a rare and generally benign movement disorder of the chin yet with potentially debilitating complications. Due to its rarity, previous literature was limited to only case reports or series with critical knowledge gap on its natural history, prognosis, and management. We aimed to establish the natural history, prognosis, and treatment for geniospasm. METHODS: A systematic review on case reports or series was performed with literature search on PubMed and Google Scholar, from inception through December 2021. The quality of the reports was assessed with low-quality articles excluded for analyses other than demographics. RESULTS: Forty-one articles were included for demographic analysis (n = 489) while forty articles for other analyses (n = 451). There was only slight male preponderance of this disease in our cohort (Male:Female = 1.2:1) with 98.6% having family history of geniospasm, 68.1% having onset below 1 year of age, 91.4% having emotional triggers of the symptoms, 25.7% having geniospasm in sleep, 100% involving mentalis muscles, 4.9% involving muscles adjacent to mentalis, 55.2% having regular paroxysms (≥1/week, but brief in 56.3% of the cases) and only 11.1% having complications. The paroxysms reduced with age, but complete remission only happened in 9.9%. Females (p = 0.010) and those without geniospasm in sleep (p = 0.048) were associated with good outcome of the disease. Geniospasm was usually refractory to treatment except for regular botulinum toxin injections. CONCLUSION: Generally, geniospasm improved with age but complete remission was rare. Considering our review limitations, our findings should be interpreted with caution. Future studies of higher evidence level are crucial.

Association of common genetic variants with vitamin D status in Malaysian children with epilepsy.

PURPOSE: Children with epilepsy (CWE) are at risk of vitamin D deficiency. Single nucleotide polymorphisms (SNPs) affecting the vitamin D pathway are potentially important risk factors for serum 25-hydroxyvitamin D [25(OH)D] concentration. The aims of our study were to evaluate the association of vitamin d-related SNPs to serum 25(OH)D concentrations in Malaysian CWE. METHODS: Cross-sectional study of Malaysian ambulant CWE on antiseizure medication for >1 year. Sixteen SNPs in 8 genes (GC, VDR, CYP2R1, CYP24A1, CYP27B1, CYP27A1, CYP3A4, NADSYN1/DHCR7) were genotyped. Linear and logistic regression models and co-variates adjusted analyses were used. SNPs with significant associations were further analysed in a group of ethnically-matched healthy Malaysian children. RESULTS: 239 CWE were recruited (52.7% Malay, 24.3% Chinese and 23.0% Indian) with mean serum 25(OH)D of 58.8 nmol/L (SD 25.7). Prevalence of vitamin D deficiency (≤37.5 nmol/L) was 23.0%. Minor allele of GC-rs4588-A was associated with lower serum 25(OH)D in the meta-analysis of both CWE (ß -8.11, P = 0.002) and Malaysian healthy children (ß -5.08, P < 0.001), while VDR-rs7975232-A was significantly associated with reduced odds of vitamin D deficiency in Malay subgroup of CWE (OR: 0.16; 95% CI: 0.06-0.49; P = 0.001) and this association was not found in the healthy children group. CONCLUSIONS: Our results suggest that GC-rs4588 is associated with lower serum 25(OH)D concentration in both Malaysian CWE and healthy children, while VDR-rs7975232A is associated with lower risk of vitamin D deficiency in Malaysian CWE of Malay ethnicity. Our findings may assist in the genetic risk stratification of low vitamin D status among CWE.