SCN1A Channels a Wide Range of Epileptic Phenotypes: Report of Novel and Known Variants with Variable Presentations.

SCN1A, the gene encoding for the Nav1.1 channel, exhibits dominant interneuron-specific expression, whereby variants disrupting the channel's function affect the initiation and propagation of action potentials and neuronal excitability causing various types of epilepsy. Dravet syndrome (DS), the first described clinical presentation of SCN1A channelopathy, is characterized by severe myoclonic epilepsy in infancy (SMEI). Variants' characteristics and other genetic or epigenetic factors lead to extreme clinical heterogeneity, ranging from non-epileptic conditions to developmental and epileptic encephalopathy (DEE). This current study reports on findings from 343 patients referred by physicians in hospitals and tertiary care centers in Greece between 2017 and 2023. Positive family history for specific neurologic disorders was disclosed in 89 cases and the one common clinical feature was the onset of seizures, at a mean age of 17 months (range from birth to 15 years old). Most patients were specifically referred for SCN1A investigation (Sanger Sequencing and MLPA) and only five for next generation sequencing. Twenty-six SCN1A variants were detected, including nine novel causative variants (c.4567A>Τ, c.5564C>A, c.2176+2T>C, c.3646G>C, c.4331C>A, c.1130_1131delGAinsAC, c.1574_1580delCTGAGGA, c.4620A>G and c.5462A>C), and are herein presented, along with subsequent genotype-phenotype associations. The identification of novel variants complements SCN1A databases extending our expertise on genetic counseling and patient and family management including gene-based personalized interventions.

Combined exome analysis and exome depth assessment achieve a high diagnostic yield in an epilepsy case series, revealing significant genomic heterogeneity and novel mechanisms.

OBJECTIVES: Genetics of epilepsy are highly heterogeneous and complex. Lesions detected involve genes encoding various types of channels, transcription factors, and other proteins implicated in numerous cellular processes, such as synaptogenesis. Consequently, a wide spectrum of clinical presentations and overlapping phenotypes hinders differential diagnosis and highlights the need for molecular investigations toward delineation of underlying mechanisms and final diagnosis. Characterization of defects may also contribute valuable data on genetic landscapes and networks implicated in epileptogenesis. METHODS: This study reports on genetic findings from exome sequencing (ES) data of 107 patients with variable types of seizures, with or without additional symptoms, in the context of neurodevelopmental disorders. RESULTS: Multidisciplinary evaluation of ES, including ancillary detection of copy number variants (CNVs) with the ExomeDepth tool, supported a definite diagnosis in 59.8% of the patients, reflecting one of the highest diagnostic yields in epilepsy. CONCLUSION: Emerging advances of next-generation technologies and 'in silico' analysis tools offer the possibility to simultaneously detect several types of variations. Wide assessment of variable findings, specifically those found to be novel and least expected, reflects the ever-evolving genetic landscape of seizure development, potentially beneficial for increased opportunities for trial recruitment and enrollment, and optimized, even personalized, medical management.

HLA-DRB1 allele impact on pediatric multiple sclerosis in a Hellenic cohort.

BACKGROUND: Pediatric-onset multiple sclerosis (POMS) is considered a complex disease entity with many genetic and environmental factors implicated in its pathogenesis. Linkage studies in Caucasian adult populations consistently demonstrate the major histocompatibility complex and its HLA (human leukocyte antigen) polymorphisms as the genetic locus most strongly linked to MS. OBJECTIVE: To investigate the frequencies and possible clinical and imaging correlations of HLA-DRB1 alleles in a Hellenic POMS sample. METHODS: Fifty POMS patients fulfilling the IPMSSG (International Pediatric Multiple Sclerosis Study Group) criteria were enrolled using 144 adult-onset MS (AOMS) patients and 246 healthy controls for comparisons. HLA genotyping was performed with standard low-resolution sequence-specific oligonucleotide (SSO) techniques. Clinical and imaging correlations with specific HLA-DRB1 alleles were also examined. RESULTS: The HLA-DRB1*03 genotype was significantly higher in POMS patients compared to both the AOMS population (26% vs. 12.5%, p = 0.042) and the general population (26% vs. 12.6%, p = 0.004). HLA-DRB1*03-positive POMS patients had significantly more relapses (6.9 ± 4.9 vs. 4.2 ± 4.4, p = 0.005) and more thoracic spinal cord lesions than HLA-DRB1*03-negative patients (61.5% vs. 27%, p = 0.043). CONCLUSION: In our Hellenic population, HLA-DRB1*03 allele confers increased risk for POMS and it is also correlated with possibly increased disease activity, expanding the existing knowledge on HLA associations and POMS.

Increased hair cortisol and antecedent somatic complaints in children with a first epileptic seizure.

OBJECTIVE: Stress is the most frequent seizure-precipitating factor reported by patients with epilepsy, while stressful life events may increase seizure susceptibility in humans. In this study, we investigated the relations between both biological and behavioral measures of stress in children with a first epileptic seizure (hereafter called seizure). We hypothesized that hair cortisol, a biomarker of chronic stress reflecting approximately 3months of preceding exposure, might be increased in children with a first seizure. We also employed standardized questionnaires to examine presence of stress-related behavioral markers. METHODS: This was a cross-sectional clinical study investigating stress-related parameters in children with a first seizure (First Epileptic Seizure Group (FESG), n=22) in comparison to healthy children without seizures (Control Group, n=29). Within 24h after a first seizure, hair samples were collected from children for the determination of cortisol. In parallel, perceived stress and anxiety and depressive symptoms were examined with appropriate self- and parent-completed questionnaires, and history of stressful life events during the past year was recorded. Emotional and behavioral problems were also assessed by parent-reported validated and widely-used questionnaires. RESULTS: Higher hair cortisol measurements were observed in the FESG than control children (7.5 versus 5.0pg/mg respectively, p=0.001). The former were more likely to complain of somatic problems than the latter (59.8 vs. 55.4 according to DSM-oriented Scale, p=0.021); however, there were no differences in perceived stress and anxiety or depressive symptoms between the two groups. Using ROC analysis of hair cortisol measurements for predicting disease status, the maximum sensitivity and specificity were observed for a cut-off point of 5.25pg/mg. SIGNIFICANCE: Increased hair cortisol indicates chronic hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis prior to the first seizure. This might have contributed to the epileptogenesis process and may help explain the higher incidence of antecedent somatic complaints in the first seizure group.

Acute disseminated encephalomyelitis after allogeneic bone marrow transplantation for pure red cell aplasia - a case report and review of the literature.

ADEM is a rare inflammatory demyelinating disease of the CNS, which usually presents after a viral infection or a vaccination. We report a 15-yr-old boy who was diagnosed with ADEM after an HLA-identical sibling allogeneic BMT for transfusion-dependent PRCA. His course was complicated with GVHD affecting the skin and lungs. Five months post-BMT, he developed neurological symptoms including sudden mental status alteration, dysarthria, facial nerve palsy, and acute paraplegia. The MRI revealed multifocal hyperintense lesions mainly in the subcortical white matter of the cerebrum, the brainstem, the basal ganglia, and the thalami. CSF examination was normal. There was no laboratory evidence of infection. The typical MRI findings and an acute monophasic clinical course were consistent with the diagnosis of ADEM. Clinical and radiological improvement was observed after treatment with high-dose steroids and IVIG. Complete neurologic recovery was achieved six months after the onset of symptoms. We present a rare case of ADEM post-BMT and review of the literature.

Complex distal 10q rearrangement in a girl with mild intellectual disability: follow up of the patient and review of the literature of non-acrocentric satellited chromosomes.

We report on an intellectually disabled girl with a de novo satellited chromosome 10 (10qs) and performed a review of the literature of the non-acrocentric satellited chromosomes (NASC). Satellites and stalks normally occur on the short arms of acrocentric chromosomes; however, the literature cites several reports of satellited non-acrocentric chromosomes, which presumably result from a translocation with an acrocentric chromosome. This is, to our knowledge, the third report of a 10qs chromosome. The phenotype observed in the proband prompted a search for a structural rearrangement of chromosome 10q. By microsatellite analysis we observed a 4 Mb deletion on the long arm of chromosome 10, approximately 145 kb from the telomere. FISH and array CGH analyses revealed a complex rearrangement involving in range from the centromere to the telomere: A 9.64 Mb 10q26.11-q26.2 duplication, a 1.3 Mb region with no copy number change, followed by a 5.62 Mb 10q26.2-q26.3 deletion and a translocation of satellite material. The homology between the repeat sequences at 10q subtelomere region and the sequences on the acrocentric short arms may explain the origin of the rearrangement and it is likely that the submicroscopic microdeletion and microduplication are responsible for the abnormal phenotype in our patient. The patient presented here, with a 15-year follow-up, manifests a distinct phenotype different from the 10q26 pure distal monosomy and trisomy syndromes.

A study of 43 patients with panayiotopoulos syndrome, a common and benign childhood seizure susceptibility.

PURPOSE: To determine prevalence, clinical, EEG features, and prognosis of Panayiotopoulos syndrome and to examine the proposition that clinical manifestations are more important than EEG findings. METHODS: We analyzed retrospectively the clinical and EEG records of 1,340 children with one or more focal seizures seen in the last 18 years, supplemented with a prospective study from 1998. Panayiotopoulos syndrome was defined by clinical criteria, mainly ictal emesis, irrespective of EEG findings. RESULTS: We analyzed 43 of 90 patients with Panayiotopoulos syndrome who were seizure free >2 years. Girls predominated. Mean age at first seizure was 5 years. Seizures consisted mainly of autonomic manifestations; ictal emesis was often the first symptom, culminating in vomiting in 86%. Of nonautonomic manifestations, lateral eye deviation was the most common; visual symptoms were exceptional. Impairment of consciousness ensued in all seizures, half of which ended with hemi or generalized convulsions. Nearly 46.5% of cases had at least one seizure >30 min, constituting autonomic status epilepticus. Seizures during sleep (84%) were more common than those in wakefulness. EEG showed occipital spikes in 29 patients. Of the other 14 cases, five had extraoccipital abnormalities or brief generalized discharges, and nine had normal awake and sleep EEG. Prognosis was excellent. All 43 children have been free of seizures for > or =2 years, 53% having a single seizure, and 47%, an average two to three seizures. CONCLUSIONS: Panayiotopoulos syndrome is common and needs wider recognition. EEG shows occipital or extraoccipital abnormalities, is normal in one third of patients, and does not determine clinical manifestations or prognosis, which is excellent despite the high prevalence of lengthy seizures.

Multiple pituitary hormone abnormalities, fever, behavioral problems, seizures and apnoic spells in a 6-year old girl.

UNLABELLED: A 6-year old girl was examined having two years previously presented a transient Cushing's syndrome, followed by recurrent hyponatremia, attributed to inappropriate ADH secretion (SIADH). The brain MRI showed no abnormalities on repeated examinations, except for a suggestion of empty sella syndrome. During the past two years she also presented recurrent episodes of a prolonged febrile illness of unknown origin. All investigations related to infectious, autoimmune neoplastic diseases, histiocytosis-X or neurosarcoidosis were negative and the fever was characterized as central. The patient also presented episodes of tonic-clonic seizures, myoclonias and behavioral problems (alternating states of irritability, sleepiness and apathy, optic and hearing illusions and phobias) with or without hyponatremia. Her cerebrospinal fluid (CSF) examination was not indicative of encephalitis and the encephalogram (EEG) showed only slowing of background activity. At the age of 4.75 years she, started to have recurrent episodes of hypopnoea/apnoea with severe desaturation and hypercapnia, occasionally requiring intubation and ventilation. She also developed unilateral miosis corneal ulceration and bilateral ptosis (oculo-sympathetic paresis). Repeat brain MRI and CT scans of the mediastinum excluded organic causes of apnoeas and of oculo-sympathetic paresis, such as neuroblastoma or lymphoma. Furthermore, on a 24 hour electrocardiogram recording, using power spectral analysis, significantly reduced heart rate variability was observed, by comparison with age-specific normal ranges. Thus the apnoeas, ptosis, miosis and temperature instability were attributed to autonomic dysfunction. During the same period, the patient presented significant growth retardation and growth hormone (GH) deficiency was confirmed during two provocative tests (peak GH levels: 3.1 and 2.9 ng/ml (normal>10). Moreover, thyrotropin (TSH) deficiency and persistent hyperprolactinemia were detected. She was started on hGH and thyroxine. She was also put on fluid restriction and increased sodium intake for her SIADH. She was advised to use O2 administration by mask in case of apnoeas. The child died at age 6 6/12 years as a result of apnoea during sleep. IN CONCLUSION: Multiple pituitary hormonal abnormalities, together with symptoms of autonomic neuropathy (apnoeas, ptosis, miosis, tachycardia, temperature instability) and encephalopathy (seizures, myoclonias and behavioral problems) developed in a 4-year old girl. The suggested diagnoses were: 1. Neurometabolic disorder, 2. Mitochondrial disorder, 3. Post infectious autoimmune process.