GABRA1-Related Disorders: From Genetic to Functional Pathways.

OBJECTIVE: Variants in GABRA1 have been associated with a broad epilepsy spectrum, ranging from genetic generalized epilepsies to developmental and epileptic encephalopathies. However, our understanding of what determines the phenotype severity and best treatment options remains inadequate. We therefore aimed to analyze the electroclinical features and the functional effects of GABRA1 variants to establish genotype-phenotype correlations. METHODS: Genetic and electroclinical data of 27 individuals (22 unrelated and 2 families) harboring 20 different GABRA1 variants were collected and accompanied by functional analysis of 19 variants. RESULTS: Individuals in this cohort could be assigned into different clinical subgroups based on the functional effect of their variant and its structural position within the GABRA1 subunit. A homogenous phenotype with mild cognitive impairment and infantile onset epilepsy (focal seizures, fever sensitivity, and electroencephalographic posterior epileptiform discharges) was described for variants in the extracellular domain and the small transmembrane loops. These variants displayed loss-of-function (LoF) effects, and the patients generally had a favorable outcome. A more severe phenotype was associated with variants in the pore-forming transmembrane helices. These variants displayed either gain-of-function (GoF) or LoF effects. GoF variants were associated with severe early onset neurodevelopmental disorders, including early infantile developmental and epileptic encephalopathy. INTERPRETATION: Our data expand the genetic and phenotypic spectrum of GABRA1 epilepsies and permit delineation of specific subphenotypes for LoF and GoF variants, through the heterogeneity of phenotypes and variants. Generally, variants in the transmembrane helices cause more severe phenotypes, in particular GoF variants. These findings establish the basis for a better understanding of the pathomechanism and a precision medicine approach in GABRA1-related disorders. Further studies in larger populations are needed to provide a conclusive genotype-phenotype correlation. ANN NEUROL 2023.

Assessing Joint Hypermobility in Preschool-Aged Children.

OBJECTIVE: To provide a revision of the Beighton score adapted for children younger than the age of 5 years, to apply the revised version in a cohort of preschool age children, and to verify the reliability of the revised version in a cohort of preschool children with genetic syndromes associated with hypermobility. STUDY DESIGN: The revised Beighton score was applied in a population of preschool children to evaluate joint hypermobility in 5 parts of the body, bilaterally (passive dorsiflexion of the fifth finger; passive hyperextension of the elbow; passive hyperextension of the knee; passive apposition of the thumb to the flexor side of the forearm; passive dorsiflexion of the ankle joint). The frequency distribution of the total scores was calculated with a range between 0 and 10. RESULTS: A total of 284 healthy preschool children (146 boys and 138 girls) and 26 preschool children with genetic disorders (15 boys and 11 girls) were assessed. Mean age was 33.6 ± 12.7 months. A score ≤4 was found in more than 90% of the whole cohort; therefore, a cut-off score >4 was used to identify hypermobility. Twenty-two of the 284 (7%) healthy children and 23 of the 26 children (89%) with genetic syndromes associated with hypermobility had a score >4. The joints reporting a greater incidence of hypermobility were "apposition of the thumb to the forearm" and "passive dorsiflexion of the ankle," in 34% and 22% respectively. No differences related to sex or age were observed. CONCLUSIONS: The revised version of the Beighton score can be used to define generalized hypermobility for children up to 5 years of age and to assess and follow-up longitudinally patients with isolated hypermobility or those in whom the laxity is associated with other clinical features.

Changes of DNA quality and meat physicochemical properties in bovine supraspinatus muscle during microwave heating.

BACKGROUND: The responses of foods to microwave exposure are usually evaluated only in terms of physicochemical properties, thus undervaluing the importance of DNA in an authentication process by methods based on polymerase chain reaction (PCR). In this study, the time effect of microwave heating on some meat physicochemical properties and DNA quality has been investigated. RESULTS: Cooking loss, instrumental colour, pH and other physicochemical parameters varied significantly during microwave cooking, reaching the lowest/highest values after 2.5 min of cooking. The exposure of meat to microwaves was found to affect characteristically the quality of extracted DNA (i.e. yield, purity and degradation). PCR products of both mitochondrial and nuclear regions were successfully observed in all samples. However, the band for large fragments became progressively fainter as treatment time increased. CONCLUSIONS: Microwave heating caused physicochemical changes in bovine supraspinatus muscle and influenced characteristically the yield and integrity of the extracted DNA, indicating that an accurate DNA quantification and a rational choice of the genes (i.e. mtDNA versus nDNA, fragment size, etc.) to be amplified are fundamental in an authentication process by PCR-based methods.

Status epilepticus in BRAF-related cardio-facio-cutaneous syndrome: Focus on neuroimaging clues to physiopathology.

OBJECTIVE: Cardio-facio-cutaneous syndrome (CFC) is a genetic disorder due to variants affecting genes coding key proteins of the Ras/MAPK signaling pathway. Among the different features of CFC, neurological involvement, including cerebral malformations and epilepsy, represents a common and clinically relevant aspect. Status epilepticus (SE) is a recurrent feature, especially in a specific subgroup of CFC patients with developmental and epileptic encephalopathy (DEE) and history of severe pharmacoresistant epilepsy. Here we dissect the features of SE in CFC patients with a particular focus on longitudinal magnetic resonance imaging (MRI) findings to identify clinical-radiological patterns and discuss the underlying physiopathology. METHODS: We retrospectively analyzed clinical, electroencephalogram (EEG), and MRI data collected in a single center from a cohort of 23 patients with CFC carrying pathogenic BRAF variants who experienced SE during a 5-year period. RESULTS: Seven episodes of SE were documented in 5 CFC patients who underwent EEG and MRI at baseline. MRI was performed during SE/within 72 hours from SE termination in 5/7 events. Acute/early post-ictal MRI findings showed heterogenous abnormalities: restricted diffusion in 2/7, focal area of pcASL perfusion change in 2/7, focal cortical T2/FLAIR hyperintensity in 2/7. Follow-up images were available for 4/7 SE. No acute changes were detected in 2/7 (MRI performed 4 days after SE termination). SIGNIFICANCE: Acute focal neuroimaging changes concomitant with ictal EEG focus were present in 5/7 episodes, though with different findings. The heterogeneous patterns suggest different contributing factors, possibly including the presence of focal cortical malformations and autoinflammation. When cytotoxic edema is revealed by MRI, it can be followed by permanent structural damage, as already observed in other genetic conditions. A better understanding of the physiopathology will provide access to targeted treatments allowing to prevent long-term adverse neurological outcome. PLAIN LANGUAGE SUMMARY: Cardio-facio-cutaneous syndrome is a genetic disorder that often causes prolonged seizures known as status epilepticus. This study has a focus on electroclinical and neuroimaging patterns in patients with cardio-facio-cutaneous syndrome. During these status epilepticus episodes, we found different abnormal brain imaging patterns in patients, indicating various causes like brain malformations and inflammation. Understanding these patterns could help doctors find specific treatments, protecting cardio-facio-cutaneous syndrome patients from long-term brain damage.

Visual Function in Children with GNAO1-Related Encephalopathy.

BACKGROUND: GNAO1-related encephalopathies include a broad spectrum of developmental disorders caused by de novo heterozygous mutations in the GNAO1 gene, encoding the G (o) subunit α of G-proteins. These conditions are characterized by epilepsy, movement disorders and developmental impairment, in combination or as isolated features. OBJECTIVE: This study aimed at describing the profile of neurovisual competences in children with GNAO1 deficiency to better characterize the phenotype of the disease spectrum. METHODS: Four male and three female patients with confirmed genetic diagnosis underwent neurological examination, visual function assessment, and neurovisual and ophthalmological evaluation. Present clinical history of epilepsy and movement disorders, and neuroimaging findings were also evaluated. RESULTS: The assessment revealed two trends in visual development. Some aspects of visual function, such as discrimination and perception of distance, depth and volume, appeared to be impaired at all ages, with no sign of improvement. Other aspects, reliant on temporal lobe competences (ventral stream) and more related to object-face exploration, recognition and environmental control, appeared to be preserved and improved with age. SIGNIFICANCE: Visual function is often impaired, with patterns of visual impairment affecting the ventral stream less.

Heart rate variability alterations in Dravet Syndrome: The role of status epilepticus and a possible association with mortality risk.

PURPOSE: Preliminary data suggest that patients with Dravet Syndrome (DS) have a reduced heart rate variability (HRV). This seems particularly evident in patients who experienced sudden unexpected death in epilepsy (SUDEP). This study aims at confirming these findings in a larger cohort and at defining clinical, genetic or electroencephalographic predictors of HRV impairment in DS patients. METHODS: DS patients followed at our Institution performed a 24h-ECG Holter to derive HRV parameters. We used as control population patients with epilepsy (PWEs) and healthy controls (HCs). In DS patients, we assessed the impact of different clinical, neurophysiological and genetic features on HRV alterations through multiple linear regression. After a mean follow-up of 7.4 ± 3.2 years since the HRV assessment, all DS patients were contacted to record death or life-threatening events. RESULTS: 56 DS patients had a significantly reduced HRV compared to both HCs and PWEs. A recent history of status epilepticus (SE) was the only significant predictor of lower HRV in the multivariate analysis. At follow-up, only one patient died; her HRV was lower than that of all the controls and was in the low range for DS patients. CONCLUSION: We describe for the first time an association between SE and HRV alterations in DS. Further studies on other SCN1A-related phenotypes and other epilepsies with frequent SE will help clarify this finding. Compared to the literature, our cohort showed better HRV and lower mortality. Although limited, this observation reinforces the role of HRV as a biomarker for mortality risk in DS.

Fighting autoinflammation in FIRES: The role of interleukins and early immunomodulation.

Febrile infection-related epilepsy syndrome (FIRES) is a challenging condition with unfavorable outcome in most cases. Preliminary evidence suggests that some interleukins, in particular IL-1 Receptor Antagonist (IL-1RA), could be elevated due to a functional deficiency of anti-inflammatory pathways. Therefore, treatment strategies acting on innate immunity could represent a targeted treatment. We describe the case of an 11-year-old child with super-refractory status epilepticus (SE), lasting more than two months. After being treated aggressively with antiseizure medications, anesthetics and empiric treatment for autoimmune encephalitis without success, she responded to anakinra and ketogenic diet. Escalation of the therapy was supported by the finding of a very high serum level of IL-1RA. This immunomodulatory approach allowed to discharge the child from intensive care 48 days after the SE onset. After more than one year follow-up the patient has moderate intellectual disability but with good language skills; she is seizure free and without motor deficits. This case suggests that serum IL-1RA serum levels may help to support treatment escalation. Moreover, anakinra and ketogenic diet represent encouraging immunomodulatory strategies which deserve further studies and could potentially have a synergistic effect. Finally, structured neuropsychological testing is an important outcome measure that will help to define the effectiveness of different treatment strategies.

Co-Occurrence of Fragile X Syndrome with a Second Genetic Condition: Three Independent Cases of Double Diagnosis.

Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and autism caused by the instability of a CGG trinucleotide repeat in exon 1 of the FMR1 gene. The co-occurrence of FXS with other genetic disorders has only been occasionally reported. Here, we describe three independent cases of FXS co-segregation with three different genetic conditions, consisting of Duchenne muscular dystrophy (DMD), PPP2R5D--related neurodevelopmental disorder, and 2p25.3 deletion. The co-occurrence of DMD and FXS has been reported only once in a young boy, while in an independent family two affected boys were described, the elder diagnosed with FXS and the younger with DMD. This represents the second case in which both conditions coexist in a 5-year-old boy, inherited from his heterozygous mother. The next double diagnosis had never been reported before: through exome sequencing, a girl with FXS who was of 7 years of age with macrocephaly and severe psychomotor delay was found to carry a de novo variant in the PPP2R5D gene. Finally, a maternally inherited 2p25.3 deletion associated with a decreased level of the MYT1L transcript, only in the patient, was observed in a 33-year-old FXS male with severe seizures compared to his mother and two sex- and age-matched controls. All of these patients represent very rare instances of genetic conditions with clinical features that can be modified by FXS and vice versa.

Cortical Visual Impairment in CDKL5 Deficiency Disorder.

BACKGROUND: CDKL5 deficiency disorder (CDD) is a developmental encephalopathy caused by pathogenic variants in the gene cyclin-dependent kinase-like 5. Cerebral visual impairment (CVI) is frequent in patients with CDD. In addition to being recognized as a specific feature of the pathology, it has been suggested that visual impairment may correlate with neurodevelopmental outcome and epilepsy severity, but no systematic behavioral visual assessment has been performed. The aim of our study was to evaluate clinical and electrophysiological profile of CVI in patients with CDD, to correlate various aspects of visual function to neurodevelopmental and epileptic features. METHODS: The study included all patients with CDD from the National Pathology Registry. All patients underwent neurological examination, a disease-specific functional assessment, structured clinical evaluation of visual functions, including pattern reversal visual evoked potential (VEP), and a detailed monitoring of epileptic features, including video-EEG. RESULTS: All the 11 patients recorded in the CDKL5 national registry, 10 females and one male, age range of 1.5 to 24 years (mean 9, SD 7.7, median 6.5), were enrolled. Visual function is impaired in all patients; in particular, visual fields, visual acuity, contrast sensitivity, and stereopsis were consistently abnormal whereas other aspects, such as fixing and tracking, were relatively preserved. Pattern reversal VEP was abnormal in nearly 80% of our patients. No correlation was found among CVI severity, age, level of psychomotor development, EEG abnormalities, and pathology stages even if an overall less abnormal EEG pattern was more often associated with better visual results. CONCLUSION: In conclusion, CVI can be considered as a major feature of CDD with a diffuse involvement in several behavioral and electrophysiological aspects. Larger cohorts will help to better clarify the possible prognostic role of EEG severity in predicting both visual and developmental abnormalities.

Recent advances in treatment of epilepsy-related sodium channelopathies.

Voltage-gated sodium channels (VGSCs) play a crucial role in generation of action potentials. Pathogenic variants in the five human brain expressed VGSC genes, SCN1A, SCN2A, SCN3A, SCN8A and SCN1B have been associated with a spectrum of epilepsy phenotypes and neurodevelopmental disorders. In the last decade, next generation sequencing techniques have revolutionized the way we diagnose these channelopathies, which is paving the way towards precision medicine. Knowing the functional effect (Loss-of-function versus Gain-of-function) of a variant is not only important for understanding the underlying pathophysiology, but it is particularly crucial to orient therapeutic decisions. Here we provide a review of the literature dealing with treatment options in epilepsy-related sodium channelopathies, including the current and emerging medications.

Sleep disturbances in preschool age children with cerebral palsy: a questionnaire study.

OBJECTIVES: The study aimed to analyze (i) the prevalence of sleep disorders in pre-school children with cerebral palsy (CP) using the Sleep Disturbance Scale for Children (SDSC), (ii) the possible association with motor, cognitive and behavioral problems, and (iii) the possible differences with typically developing children matched for age and gender. METHODS: One-hundred children with CP (age range: 3-5 years, mean: 3.8 years) were assessed using the SDSC, the Gross Motor Function Classification System (GMFCS), the Wechsler Preschool and Primary Scale of Intelligence, and the Child Behaviour Check List (CBCL) to assess sleep, motor, cognitive, and behavioral problems, respectively. Further 100 healthy children matched for age and sex were assessed using the SDSC. RESULTS: An abnormal total sleep score was found in 13% of children with CP while 35% had an abnormal score on at least one SDSC factor. SDSC total score was significantly associated with pathological internalizing scores on CBCL and active epilepsy on multivariate analysis. CP group reported higher significant median scores on SDSC total, parasomnias, and difficulty in initiating and maintaining sleep factors. CONCLUSIONS: In pre-school children sleep disorders are more common in children with CP than in healthy control group and are often associated with epilepsy and behavioral problems.

Sleep disorders in children with cerebral palsy: neurodevelopmental and behavioral correlates.

OBJECTIVES: We aimed to estimate the frequency of sleep disorders in children with cerebral palsy (CP) using the Sleep Disturbance Scale for Children (SDSC) and to evaluate the relations between sleep disorders and motor, cognitive, and behavioral problems. METHODS: One hundred and sixty-five children with CP ages 6-16 years (mean age, 11years) were assessed using the SDSC, the Gross Motor Function Classification System (GMFCS), the Wechsler Intelligence Scale for Children and the Child Behavior Check List (CBCL) to assess sleep, motor, cognitive, and behavioral problems, respectively. RESULTS: An abnormal total sleep score was found in 19% of children with CP; more than 40% of children had an abnormal score on at least one SDSC factor. The SDSC total score was significantly associated (P<.01) with mental retardation, epilepsy, CBCL scores, and level 5 on the GMFCS. CONCLUSIONS: Our results confirm that sleep disorders are common in children with cerebral palsy. The relationship between motor and cognitive behavior and epilepsy should be further explored to better understand how these factors influence one another to identify effective treatments and to improve the well-being of the child.