The effects of N-acetyl-L-leucine on the improvement of symptoms in a patient with multiple sulfatase deficiency.

Saberi-Karimian M, Houra M, Jamialahmadi T, Sarvghadi P, Nikbaf M, Akhlaghi S, Sahebkar A. The Effects of N-Acetyl-L-Leucine on the Improvement of Symptoms in a Patient with Multiple Sulfatase Deficiency. Cerebellum. 2022 Dec 9:1–7. doi: 10.1007/s12311-022-01504-2. Epub ahead of print. PMID: 36482027; PMCID: PMC9735006.

Abstract

Multiple Sulfatase Deficiency (MSD) is a rare autosomal recessive disease with specific clinical findings such as psychomotor retardation and neurological deterioration. No therapy is available for this genetic disorder. Previous studies have shown that N-acetyl-L-leucine (NALL) can improve the neurological inflammation in the cerebellum.In the current study, the effects of NALL on ataxia symptoms and quality of life were explored in a patient with MSD.This study was a crossover case study. The subject, a girl aged 12 years old, received NALL at a dose of 3 g/day (1 g in the morning, 1 g in the afternoon, and 1 g in the evening). A fasting blood sample was taken from the subject to evaluate side effects before the intervention and 4 weeks after taking supplement/placebo in every study stage. The ataxia moving symptoms were evaluated using the Scale for the Assessment and Rating of Ataxia (SARA) score in every study stage. Dietary intake was measured using 24-h dietary recall before and after the intervention. The diet compositions were assessed by Nutritionist IV software. Serum IL-6 level was measured using an ELISA kit.There was no significant change in complete blood count (CBC) and serum biochemical factors in the patient with MSD after receiving NALL (3 g/day) over 4 weeks. The SARA score was reduced by 25%. The gait whose maximum score accounts for approximately one-fifth of the maximum total SARA score (8/40) was decreased. The heel-to-shin slide, the only SARA item performed without visual control, was also improved after therapy. Furthermore, there was a downward trend in the 8MWT (8.71 to 7.93 s). Regarding quality of life assessments, the parent and child reported improved quality of life index, physical health, and emotional function after taking NALL. Moreover, total energy intake was increased with NALL treatment through the study period.Supplementation with NALL at a dose of 3 g/day over 4 weeks was well tolerated and improved ataxia symptoms, quality of life measure, and serum IL-6 levels in the patient with MSD. Further proof-of-concept trials are warranted to confirm the present findings.

Efficacy and safety of N-acetyl-L-leucine in children and adults with GM2 gangliosidoses

Martakis K, Claassen J, Gascon-Bayari J, Goldschagg N, Hahn A, Hassan A, Hennig A, Jones S, Kay R, Lau H, Perlman S, Sharma R, Schneider S, Bremova-Ertl T. Efficacy and Safety of N-Acetyl-L-Leucine in Children and Adults With GM2 Gangliosidoses. Neurology. 2022 Dec 1:10.1212/WNL.0000000000201660. doi: 10.1212/WNL.0000000000201660. Epub ahead of print. PMID: 36456200.

Abstract

Background and objective: GM2 gangliosidoses (Tay-Sachs and Sandhoff diseases) are rare, autosomal-recessive, neurodegenerative diseases with no available symptomatic or disease modifying treatments. This clinical trial investigated N-acetyl-L-leucine (NALL), an orally administered, modified amino acid in pediatric (≥ 6 years) and adult patients with GM2 gangliosidoses.

Methods: In this Phase IIb, multi-national, open-label, rater-blinded study (IB1001-202), male and female patients aged ≥6 years with a genetically confirmed diagnosis of GM2 gangliosidoses received orally-administered NALL for a 6-week treatment period (4 g/day in patients ≥13 years, weight-tiered doses for patients 6-12 years), followed by a 6-week post-treatment washout period. For the primary Clinical Impression of Change in Severity analysis, patient performance on a pre-determined primary anchor test (the 8-Meter Walk Test or the 9-Hole Peg Test) at baseline, after 6 weeks on NALL, and again after a 6-week washout period, was videoed and evaluated centrally by blinded raters. Secondary outcomes included assessments of ataxia, clinical global impression, and quality of life.

Results: 30 patients between the age of 6 and 55 were enrolled. 29 had an on-treatment assessment and were included in the primary modified intention-to-treat analysis. The study met its CI-CS primary endpoint (mean difference 0.71, SD=2.09, 90% CI 0.00, 1.50, p=0.039), as well as secondary measures of ataxia and global impression. NALL was safe and well-tolerated, with no serious adverse reactions.

Conclusions: Treatment with NALL was associated with statistically significant and clinically-relevant changes in functioning and quality of life in patients with GM2 gangliosidosis. NALL was safe and well-tolerated, contributing to an overall favourable risk: benefit profile. NALL is a promising, easily administered (oral) therapeutic option for these rare, debilitating diseases with immense unmet medical needs.

Classification of evidence: This study provides Class IV evidence that NALL improves outcomes for patients with GM2 gangliosidoses.

ZBTB11 dysfunction

Inspired by a patient

Sumathipala D, Strømme P, Fattahi Z, Lüders T, Sheng Y, Kahrizi K, Einarsen IH, Sloan JL, Najmabadi H, van den Heuvel L, Wevers RA, Guerrero-Castillo S, Mørkrid L, Valayannopoulos V, Backe PH, Venditti CP, van Karnebeek CD, Nilsen H, Frengen E, Misceo D. ZBTB11 dysfunction: spectrum of brain abnormalities, biochemical signature and cellular consequences. Brain. 2022 Jul 29;145(7):2602-2616. doi: 10.1093/brain/awac034. PMID: 35104841; PMCID: PMC9337812.

Abstract

Bi-allelic pathogenic variants in ZBTB11 have been associated with intellectual developmental disorder, autosomal recessive 69 (MRT69; OMIM 618383). We report five patients from three families with novel, bi-allelic variants in ZBTB11. We have expanded the clinical phenotype of MRT69, documenting varied severity of atrophy affecting different brain regions and described combined malonic and methylmalonic aciduria as a biochemical manifestation. As ZBTB11 encodes for a transcriptional regulator, we performeded chromatin immunoprecipitation-sequencing targeting ZBTB11 in fibroblasts from patients and controls. Chromatin immunoprecipitation-sequencing revealed binding of wild-type ZBTB11 to promoters in 238 genes, among which genes encoding proteins involved in mitochondrial functions and RNA processing are over-represented. Mutated ZBTB11 showed reduced binding to 61 of the targeted genes, indicating that the variants act as loss of function. Most of these genes are related to mitochondrial functions. Transcriptome analysis of the patient fibroblasts revealed dysregulation of mitochondrial functions. In addition, we uncovered that reduced binding of the mutated ZBTB11 to ACSF3 leads to decreased ACSF3 transcript level, explaining combined malonic and methylmalonic aciduria. Collectively, these results expand the clinical spectrum of ZBTB11-related neurological disease and give insight into the pathophysiology in which the dysfunctional ZBTB11 affect mitochondrial functions and RNA processing contributing to the neurological and biochemical phenotypes.

Global prevalence of congenital anencephaly

Salari N, Fatahi B, Fatahian R, Mohammadi P, Rahmani A, Darvishi N, Keivan M, Shohaimi S, Mohammadi M. Global prevalence of congenital anencephaly: a comprehensive systematic review and meta-analysis. Reprod Health. 2022 Oct 17;19(1):201. doi: 10.1186/s12978-022-01509-4. PMID: 36253858; PMCID: PMC9575217. 

Abstract

Background: Anencephaly is a fatal congenital anomaly characterized by the absence of brain hemispheres and cranial arch. Timely preventive measures can be taken by knowing the exact prevalence of this common neural tube defect; thus, carried out through systematic review and meta-analysis, the present study was conducted to determine the worldwide prevalence, incidence and mortality of anencephaly.

Methods: Cochran's seven-step instructions were used as the guideline. Having determined the research question and inclusion and exclusion criteria, we studied MagIran, SID, Science Direct, WoS, Web of Science, Medline (PubMed), Scopus, and Google Scholar databases. Moreover, the search strategy in each database included using all possible keyword combinations with the help of "AND" and "OR" operators with no time limit to 2021. The I2 test was used to calculate study heterogeneity, and Begg and Mazumdar rank correlation tests were employed to assess the publication bias. Data were analyzed by Comprehensive Meta-Analysis software (Version 2).

Results: In this study, the statements of Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) were used. In the first stage, 1141 articles were found, of which 330 duplicate studies were omitted. 371 articles were deleted based on the inclusion and exclusion criteria by reviewing the title and abstract of the study. 58 articles were removed by reviewing the full text of the article because it was not relevant to the research. 360 studies with a sample size of 207,639,132 people were considered for the meta-analysis. Overall estimate of the prevalence, incidence and attenuation of anencephaly worldwide were 5.1 per ten thousand births (95% confidence interval 4.7-5.5 per ten thousand births), 8.3 per ten thousand births (95% confidence interval 5.5-9.9 per ten thousand births), 5.5 per ten thousand births (95% confidence interval 1.8-15 per ten thousand births) respectively the highest of which according to the subgroup analysis, belonged to the Australian continent with 8.6 per ten thousand births (95% confidence interval 7.7-9.5 per ten thousand births).

Conclusion: The overall prevalence of anencephaly in the world is significant, indicating the urgent need for preventive and treating measures.

GABRA1 mutations

Inspired by a patient

Nwosu G, Reddy SB, Riordan HRM, Kang JQ. Variable Expression of GABAA Receptor Subunit Gamma 2 Mutation in a Nuclear Family Displaying Developmental and Encephalopathic Phenotype. Int J Mol Sci. 2022 Aug 26;23(17):9683. doi: 10.3390/ijms23179683. PMID: 36077081; PMCID: PMC9456057.

Abstract

Mutations in GABAA receptor subunit genes (GABRs) are a major etiology for developmental and epileptic encephalopathies (DEEs). This article reports a case of a genetic abnormality in GABRG2 and updates the pathophysiology and treatment development for mutations in DEEs based on recent advances. Mutations in GABRs, especially in GABRA1, GABRB2, GABRB3, and GABRG2, impair GABAergic signaling and are frequently associated with DEEs such as Dravet syndrome and Lennox-Gastaut syndrome, as GABAergic signaling is critical for early brain development. We here present a novel association of a microdeletion of GABRG2 with a diagnosed DEE phenotype. We characterized the clinical phenotype and underlying mechanisms, including molecular genetics, EEGs, and MRI. We then compiled an update of molecular mechanisms of GABR mutations, especially the mutations in GABRB3 and GABRG2 attributed to DEEs. Genetic therapy is also discussed as a new avenue for treatment of DEEs through employing antisense oligonucleotide techniques. There is an urgent need to define treatment targets and explore new treatment paradigms for the DEEs, as early deployment could alleviate long-term disabilities and improve quality of life for patients. This study highlights biomolecular targets for future therapeutic interventions, including via both pharmacological and genetic approaches.

Chen W, Ge Y, Lu J, Melo J, So YW, Juneja R, Liu L, Wang YT. Distinct Functional Alterations and Therapeutic Options of Two Pathological De Novo Variants of the T292 Residue of GABRA1 Identified in Children with Epileptic Encephalopathy and Neurodevelopmental Disorders. Int J Mol Sci. 2022 Mar 1;23(5):2723. doi: 10.3390/ijms23052723. PMID: 35269865; PMCID: PMC8911174.

Abstract

Mutations of GABAAR have reportedly led to epileptic encephalopathy and neurodevelopmental disorders. We have identified a novel de novo T292S missense variant of GABRA1 from a pediatric patient with grievous global developmental delay but without obvious epileptic activity. This mutation coincidentally occurs at the same residue as that of a previously reported GABRA1 variant T292I identified from a pediatric patient with severe epilepsy. The distinct phenotypes of these two patients prompted us to compare the impacts of the two mutants on the receptor function and to search for suitable therapeutics. In this study, we used biochemical techniques and patch-clamp recordings in HEK293 cells overexpressing either wild-type or mutated rat recombinant GABAARs. We found that the α1T292S variant significantly increased GABA-evoked whole-cell currents, shifting the dose-response curve to the left without altering the maximal response. In contrast, the α1T292I variant significantly reduced GABA-evoked currents, shifting the dose-response curve to the right with a severely diminished maximum response. Single-channel recordings further revealed that the α1T292S variant increased, while the α1T292I variant decreased the GABAAR single-channel open time and open probability. Importantly, we found that the T292S mutation-induced increase in GABAAR function could be fully normalized by the negative GABAAR modulator thiocolchicoside, whereas the T292I mutation-induced impairment of GABAAR function was largely rescued with a combination of the GABAAR positive modulators diazepam and verapamil. Our study demonstrated that α1T292 is a critical residue for controlling GABAAR channel gating, and mutations at this residue may produce opposite impacts on the function of the receptors. Thus, the present work highlights the importance of functionally characterizing each individual GABAAR mutation for ensuring precision medicine.

Feng Y, Wei ZH, Liu C, Li GY, Qiao XZ, Gan YJ, Zhang CC, Deng YC. Genetic variations in GABA metabolism and epilepsy. Seizure. 2022 Oct;101:22-29. doi: 10.1016/j.seizure.2022.07.007. Epub 2022 Jul 15. PMID: 35850019.

Abstract

Epilepsy is a paroxysmal brain disorder that results from an imbalance between neuronal excitation and inhibition. Gamma-aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the brain and plays an important role in the occurrence and development of epilepsy. Abnormalities in all aspects of GABA metabolism, including GABA synthesis, transport, genes encoding GABA receptors, and GABA inactivation, may lead to epilepsy. GABRA1, GABRA2, GABRA5, GABRB1, GABRB2, GABRB3, GABRG2 and GABBR2 are genes that encode GABA receptors and are commonly associated with epilepsy. Mutations of these genes lead to a variety of epilepsy syndromes with different clinical phenotypes, primarily by down regulating receptor expression and reducing the amplitude of GABA-evoked potentials. GABA is metabolized by GABA transaminase and succinate semi aldehyde dehydrogenase, which are encoded by the ABAT and ALDH5A1 genes, respectively. Mutations of these genes result in symptoms related to deficiency of GABA transaminase and succinate semi aldehyde dehydrogenase, such as epilepsy and cognitive impairment. Most of the variation in genes associated with GABA metabolism are accompanied by developmental disorders. This review focuses on advances in understanding the relationship between genetic variation in GABA metabolism and epilepsy to establish a basis for the accurate diagnosis and treatment of epilepsy.

International consensus recommendations for management of New Onset Refractory Status Epilepticus (NORSE)

Wickstrom R, Taraschenko O, Dilena R, Payne ET, Specchio N, Nabbout R, Koh S, Gaspard N, Hirsch LJ; International NORSE Consensus Group. International consensus recommendations for management of New Onset Refractory Status Epilepticus (NORSE) incl. Febrile Infection-Related Epilepsy Syndrome (FIRES): Statements and Supporting Evidence. Epilepsia. 2022 Aug 23. doi: 10.1111/epi.17397. Epub ahead of print. PMID: 35997591.

Abstract

Objective: To develop consensus-based recommendations for the management of adult and paediatric patients with NORSE/FIRES based on best evidence and experience.

Methods: The Delphi methodology was followed. A facilitator group of 9 experts was established, who defined the scope, users and suggestions for recommendations. Following a review of the current literature, recommendation statements concerning diagnosis, treatment and research directions were generated which were then voted on a scale of 1 (strongly disagree) to 9 (strongly agree) by a panel of 48 experts in the field. Consensus that a statement was appropriate was reached if the median score was greater or equal to 7, and inappropriate if the median score was less than or equal to 3. The analysis of evidence was mapped to the results of each statement included in the Delphi survey.

Results: Overall, 85 recommendation statements achieved consensus. The recommendations are divided into five sections: 1) disease characteristics, 2) diagnostic testing and sampling, 3) acute treatment, 4) treatment in the post-acute phase, and 5) research, registries and future directions in NORSE/FIRES. The detailed results and discussion of all 85 statements are outlined herein. A corresponding summary of findings and practical flowsheets are presented in a companion article.

Significance: This detailed analysis offers insight into the supporting evidence and the current gaps in the literature that are associated with expert consensus statements related to NORSE/FIRES. The recommendations generated by this consensus can be used as a guide for the diagnosis, evaluation, and management of patients with NORSE/FIRES, and for planning of future research.

Autoimmune encephalitis with autoantibodies to NMDAR1 following herpes encephalitis in children and adolescents

Quade A, Rostasy K, Wickström R, Aydin ÖF, Sartori S, Nosadini M, Knierim E, Kluger G, Korinthenberg R, Stüve B, Waltz S, Leiz S, Häusler M. Autoimmune Encephalitis with Autoantibodies to NMDAR1 following Herpes Encephalitis in Children and Adolescents. Neuropediatrics. 2022 Dec 21. doi: 10.1055/s-0042-1757706. Epub ahead of print. PMID: 36543183.

Abstract

Herpes simplex virus (HSV) type 1 is a frequent pathogen causing infectious encephalitis (HSVE). Early treatment with intravenous acyclovir has led to a significant decrease in mortality. However, especially in children, deterioration during or after HSVE may occur without any evidence of HSV reactivation or improvement following repeated antiviral therapy. Here, we report 15 patients (age range 3 months to 15 years) who suffered from autoimmune encephalitis with autoantibodies to NMDAR1 following Herpes encephalitis, presenting with movement abnormalities (young children) or neuropsychiatric symptoms (older children) as major complaints, respectively. The diagnosis was based on positive cerebrospinal fluid (CSF) and/or serum anti-NMDAR-antibodies with two children showing only positive CSF antibody findings. The time lag between first symptoms and diagnosis of autoimmune encephalitis was significantly longer than between first symptoms and diagnosis of HSVE (p <0.01). All patients improved during immunosuppressive treatment, during which plasmapheresis or rituximab treatments were applied in 11 patients, irrespective of their age. Despite immunotherapy, no patients relapsed with HSVE. Early diagnosis and treatment of autoimmune encephalitis after HSVE may be associated with a better outcome so that high clinical awareness and routine testing for anti-NMDAR-antibodies after HSVE seems advisable. If autoimmune encephalitis is suspected, antibody testing should also be performed on CSF if negative in serum.