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Nature Cell Biology Feb 2024Lysosomal storage disorders (LSDs), which are characterized by genetic and metabolic lysosomal dysfunctions, constitute over 60 degenerative diseases with considerable...
Lysosomal storage disorders (LSDs), which are characterized by genetic and metabolic lysosomal dysfunctions, constitute over 60 degenerative diseases with considerable health and economic burdens. However, the mechanisms driving the progressive death of functional cells due to lysosomal defects remain incompletely understood, and broad-spectrum therapeutics against LSDs are lacking. Here, we found that various gene abnormalities that cause LSDs, including Hexb, Gla, Npc1, Ctsd and Gba, all shared mutual properties to robustly autoactivate neuron-intrinsic cGAS-STING signalling, driving neuronal death and disease progression. This signalling was triggered by excessive cytoplasmic congregation of the dsDNA and DNA sensor cGAS in neurons. Genetic ablation of cGAS or STING, digestion of neuronal cytosolic dsDNA by DNase, and repair of neuronal lysosomal dysfunction alleviated symptoms of Sandhoff disease, Fabry disease and Niemann-Pick disease, with substantially reduced neuronal loss. We therefore identify a ubiquitous mechanism mediating the pathogenesis of a variety of LSDs, unveil an inherent connection between lysosomal defects and innate immunity, and suggest a uniform strategy for curing LSDs.
Topics: Humans; Lysosomal Storage Diseases; Niemann-Pick Disease, Type C; Lysosomes; Immunity, Innate; Nucleotidyltransferases
PubMed: 38253667
DOI: 10.1038/s41556-023-01339-x -
European Journal of Neurology Sep 2023Since the results of previous studies regarding the safety and efficacy of miglustat in GM2 gangliosidosis (GM2g) were inconsistent, we aimed to assess miglustat therapy... (Review)
Review
BACKGROUND
Since the results of previous studies regarding the safety and efficacy of miglustat in GM2 gangliosidosis (GM2g) were inconsistent, we aimed to assess miglustat therapy in GM2g patients.
METHODS
This study followed the latest version of PRISMA. We included the observational or interventional studies reporting GM2g patients under miglustat therapy by searching PubMed, Web of Science, and Scopus. Data extracted included the natural history of individual patient data, as well as the safety and efficacy of miglustat in GM2g patients. The quality assessment was performed using the Joanna Briggs Institute Critical Appraisal checklist.
RESULTS
A total of 1023 records were identified and reduced to 621 after removing duplicates. After screening and applying the eligibility criteria, 10 articles and 2 abstracts met the inclusion criteria. Overall, the studies represented 54 patients with GM2g under treatment with miglustat and 22 patients with GM2g in the control group. Among patients with available data, 14 and 54 have been diagnosed with Sandhoff disease and Tay-Sachs disease, respectively. Patients included in this review consisted of 23 infantile, 4 late-infantile, 18 juvenile, and 31 adult-onset GM2g.
CONCLUSIONS
Although miglustat should not be considered a definite treatment for GM2g, it appears that patients, particularly those with infantile or late-infantile GM2g, could benefit from miglustat therapy to some extent. We also make some suggestions regarding future studies presenting their findings in a standard format to facilitate pooling the available data in such rare diseases for a more comprehensive conclusion.
Topics: Adult; Humans; Gangliosidoses, GM2; 1-Deoxynojirimycin
PubMed: 37209042
DOI: 10.1111/ene.15871 -
Annals of Neurology Nov 2023GM2 gangliosidosis is usually fatal by 5 years of age in its 2 major subtypes, Tay-Sachs and Sandhoff disease. First reported in 1881, GM2 gangliosidosis has no...
OBJECTIVE
GM2 gangliosidosis is usually fatal by 5 years of age in its 2 major subtypes, Tay-Sachs and Sandhoff disease. First reported in 1881, GM2 gangliosidosis has no effective treatment today, and children succumb to the disease after a protracted neurodegenerative course and semi-vegetative state. This study seeks to further develop adeno-associated virus (AAV) gene therapy for human translation.
METHODS
Cats with Sandhoff disease were treated by intracranial injection of vectors expressing feline β-N-acetylhexosaminidase, the enzyme deficient in GM2 gangliosidosis.
RESULTS
Hexosaminidase activity throughout the brain and spinal cord was above normal after treatment, with highest activities at the injection sites (thalamus and deep cerebellar nuclei). Ganglioside storage was reduced throughout the brain and spinal cord, with near complete clearance in many regions. While untreated cats with Sandhoff disease lived for 4.4 ± 0.6 months, AAV-treated cats lived to 19.1 ± 8.6 months, and 3 of 9 cats lived >21 months. Correction of the central nervous system was so effective that significant increases in lifespan led to the emergence of otherwise subclinical peripheral disease, including megacolon, enlarged stomach and urinary bladder, soft tissue spinal cord compression, and patellar luxation. Throughout the gastrointestinal tract, neurons of the myenteric and submucosal plexuses developed profound pathology, demonstrating that the enteric nervous system was inadequately treated.
INTERPRETATION
The vector formulation in the current study effectively treats neuropathology in feline Sandhoff disease, but whole-body targeting will be an important consideration in next-generation approaches. ANN NEUROL 2023;94:969-986.
Topics: Child; Animals; Cats; Humans; Sandhoff Disease; Multiple Organ Failure; Genetic Vectors; Central Nervous System; Gangliosidoses, GM2; Genetic Therapy
PubMed: 37526361
DOI: 10.1002/ana.26756 -
Molecular Genetics and Metabolism... Jun 2024Selective screening for inherited metabolic disorders (IMD) began in Cyprus in 1990. Over the last thirty-three years 7388 patients were investigated for IMD and 200...
Selective screening for inherited metabolic disorders (IMD) began in Cyprus in 1990. Over the last thirty-three years 7388 patients were investigated for IMD and 200 diagnoses were made (diagnostic yield 2.7%). The existence of a single laboratory of Biochemical Genetics for the whole island facilitated the creation of a national registry for IMD. The minimal prevalence of IMD in Cyprus is 53.3 cases per 100,000 live births. The most common group are disorders of amino acid metabolism (41.0%), followed by disorders of carbohydrate metabolism (16.5%), disorders of complex molecule degradation (16.5%), mitochondrial disorders (10.5%) and disorders of vitamin and co-factor metabolism (5.5%). Hyperphenylalaninaemia is the most common IMD (14.0%) followed by galactosaemia (7.0%), glutaric aciduria type I (5.5%) and MSUD (4.0%). Some disorders were found to have a relatively high incidence in specific communities, for example Sandhoff disease among the Cypriot Maronites and GM1 gangliosidosis in one particular area of the island. Other disorders were found to have a relatively higher overall incidence, compared to other Caucasian populations, for example galactosaemia, glutaric aciduria type I and MSUD, while fatty acid oxidation defects, Gaucher disease and classic PKU were found to have a relatively lower incidence. Molecular characterization of selected disorders revealed many novel genetic variants, specific to the Cypriot population.
PubMed: 38694234
DOI: 10.1016/j.ymgmr.2024.101083 -
Molecular Genetics and Metabolism... Dec 2023Late-onset forms of GM2 gangliosidosis-mainly, Tay-Sachs disease and Sandhoff disease-are under-recognized in clinical practice. In these rare lysosomal storage...
Late-onset forms of GM2 gangliosidosis-mainly, Tay-Sachs disease and Sandhoff disease-are under-recognized in clinical practice. In these rare lysosomal storage disorders, deficiency of β-hexosaminidase A results in excessive accumulation of GM2 ganglioside primarily within neurons, leading to cell death and progressive neurodegenerative symptoms, including ataxia, dysarthria, muscle weakness, tremors, atrophy, and psychosis. Presentation is variable and often mimics more common neurodegenerative disorders. We conducted semi-structured interviews on GM2 gangliosidoses diagnosis and treatment with five experts, 30 neurologists, and 28 patients and caregivers. Symptom onset occurred during adolescence/early adulthood in 92% of patients (median age: 14 years). Patients first visited a healthcare provider at a median age of 20 years and received a GM2 diagnosis at a median age of 26 years. Nearly all patients reported problems with their legs and balance starting from symptom onset. Problems with memory, attention span, speech and fatigue were reported more after diagnosis. Patients visited an average of eight healthcare providers before receiving a diagnosis; 64% were diagnosed by a neurologist. Four neurologists (13%) in our sample were aware that there are late-onset forms of GM2 gangliosidosis. The path to diagnosis is long for this late-onset form of a classically fatal infantile disease.
PubMed: 38053937
DOI: 10.1016/j.ymgmr.2023.101014 -
International Journal of Molecular... Sep 2023GM2 gangliosidoses are a group of neurodegenerative lysosomal storage disorders that are characterized by the accumulation of GM2 gangliosides (GM2), leading to rapid...
GM2 gangliosidoses are a group of neurodegenerative lysosomal storage disorders that are characterized by the accumulation of GM2 gangliosides (GM2), leading to rapid neurological decline and death. The hydrolysis of GM2 requires the specific synthesis, processing, and combination of products of three genes-, , and -within the cell's lysosomes. Mutations in these genes result in Tay-Sachs disease, Sandhoff disease, or AB-variant GM2 gangliosidosis (ABGM2), respectively. ABGM2, the rarest of the three types, is characterized by a mutation in the gene, which encodes the GM2 activator (GM2A) protein. Being a monogenic disease, gene therapy is a plausible and likely effective method of treatment for ABGM2. This study aimed at assessing the effects of administering a one-time intravenous treatment of single-stranded Adeno-associated virus serotype 9 (ssAAV9)- viral vector at a dose of 1 × 10 vector genomes (vg) per kilogram per mouse in an ABGM2 mouse model (). was administered at 1-day (neonatal) or 6-weeks of age (adult-stage). The results demonstrated that, in comparison to mice that received a vehicle injection, the treated mice had reduced GM2 accumulation within the central nervous system and had long-term persistence of vector genomes in the brain and liver. This proof-of-concept study is a step forward towards the development of a clinically therapeutic approach for the treatment of patients with ABGM2.
Topics: Humans; Animals; Mice; Dependovirus; Serogroup; Tay-Sachs Disease; Gangliosidoses, GM2; G(M2) Activator Protein; Genetic Therapy
PubMed: 37834060
DOI: 10.3390/ijms241914611 -
Molecular Genetics and Metabolism Jun 2024The late-onset GM2 gangliosidoses, comprising late-onset Tay-Sachs and Sandhoff diseases, are rare, slowly progressive, neurogenetic disorders primarily characterized by...
The late-onset GM2 gangliosidoses, comprising late-onset Tay-Sachs and Sandhoff diseases, are rare, slowly progressive, neurogenetic disorders primarily characterized by neurogenic weakness, ataxia, and dysarthria. The aim of this longitudinal study was to characterize the natural history of late-onset GM2 gangliosidoses using a number of clinical outcome assessments to measure different aspects of disease burden and progression over time, including neurological, functional, and quality of life, to inform the design of future clinical interventional trials. Patients attending the United States National Tay-Sachs & Allied Diseases Family Conference between 2015 and 2019 underwent annual clinical outcome assessments. Currently, there are no clinical outcome assessments validated to assess late-onset GM2 gangliosidoses; therefore, instruments used or designed for diseases with similar features, or to address various aspects of the clinical presentations, were used. Clinical outcome assessments included the Friedreich's Ataxia Rating Scale, the 9-Hole Peg Test, and the Assessment of Intelligibility of Dysarthric Speech. Twenty-three patients participated in at least one meeting visit (late-onset Tay-Sachs, n = 19; late-onset Sandhoff, n = 4). Patients had high disease burden at baseline, and scores for the different clinical outcome assessments were generally lower than would be expected for the general population. Longitudinal analyses showed slow, but statistically significant, neurological progression as evidenced by worsening scores on the 9-Hole Peg Test (2.68%/year, 95% CI: 0.13-5.29; p = 0.04) and the Friedreich's Ataxia Rating Scale neurological examination (1.31 points/year, 95% CI: 0.26-2.35; p = 0.02). Time since diagnosis to study entry correlated with worsening scores on the 9-Hole Peg Test (r = 0.728; p < 0.001), Friedreich's Ataxia Rating Scale neurological examination (r = 0.727; p < 0.001), and Assessment of Intelligibility of Dysarthric Speech intelligibility (r = -0.654; p = 0.001). In summary, patients with late-onset GM2 gangliosidoses had high disease burden and slow disease progression. Several clinical outcome assessments suitable for clinical trials showed only small changes and standardized effect sizes (change/standard deviation of change) over 4 years. These longitudinal natural history study results illustrate the challenge of identifying responsive endpoints for clinical trials in rare, slowly progressive, neurogenerative disorders where arguably the treatment goal is to halt or decrease the rate of decline rather than improve clinical status. Furthermore, powering such a study would require a large sample size and/or a long study duration, neither of which is an attractive option for an ultra-rare disease with no available treatment. These findings support the development of potentially more sensitive late-onset GM2 gangliosidoses-specific rating instruments and/or surrogate endpoints for use in future clinical trials.
PubMed: 38870773
DOI: 10.1016/j.ymgme.2024.108512 -
Neurology Jan 2024GM2 gangliosidoses, a group of autosomal-recessive neurodegenerative lysosomal storage disorders, result from β-hexosaminidase (HEX) deficiency with GM2 ganglioside as...
BACKGROUND AND OBJECTIVES
GM2 gangliosidoses, a group of autosomal-recessive neurodegenerative lysosomal storage disorders, result from β-hexosaminidase (HEX) deficiency with GM2 ganglioside as its main substrate. Historically, GM2 gangliosidoses have been classified into infantile, juvenile, and late-onset forms. With disease-modifying treatment trials now on the horizon, a more fine-grained understanding of the disease course is needed.
METHODS
We aimed to map and stratify the clinical course of GM2 gangliosidoses in a multicenter cohort of pediatric and adult patients. Patients were stratified according to age at onset and age at diagnosis. The 2 resulting GM2 disease clusters were characterized in-depth for respective disease features (detailed standardized clinical, laboratory, and MRI assessments) and disease evolution.
RESULTS
In 21 patients with GM2 gangliosidosis (17 Tay-Sachs, 2 GM2 activator deficiency, 2 Sandhoff disease), 2 disease clusters were discriminated: an early-onset and early diagnosis cluster (type I; n = 8, including activator deficiency and Sandhoff disease) and a cluster with very variable onset and long interval until diagnosis (type II; n = 13 patients). In type I, rapid onset of developmental stagnation and regression, spasticity, and seizures dominated the clinical picture. Cherry red spot, startle reactions, and elevated AST were only seen in this cluster. In type II, problems with balance or gait, muscle weakness, dysarthria, and psychiatric symptoms were specific and frequent symptoms. Ocular signs were common, including supranuclear vertical gaze palsy in 30%. MRI involvement of basal ganglia and peritrigonal hyperintensity was seen only in type I, whereas predominant infratentorial atrophy (or normal MRI) was characteristic in type II. These types were, at least in part, associated with certain genetic variants.
DISCUSSION
Age at onset alone seems not sufficient to adequately predict different disease courses in GM2 gangliosidosis, as required for upcoming trial planning. We propose an alternative classification based on age at disease onset and dynamics, predicted by clinical features and biomarkers, into type I-an early-onset, rapid progression cluster-and type II-a variable onset, slow progression cluster. Specific diagnostic workup, including GM2 gangliosidosis, should be performed in patients with combined ataxia plus lower motor neuron weakness to identify type II patients.
Topics: Adult; Humans; Child; Sandhoff Disease; Gangliosidoses, GM2; Diagnostic Imaging; Ataxia; Disease Progression
PubMed: 38165373
DOI: 10.1212/WNL.0000000000207898 -
Neural Regeneration Research Jan 2024GM2 gangliosidoses are a group of autosomal-recessive lysosomal storage disorders. These diseases result from a deficiency of lysosomal enzyme β-hexosaminidase A...
GM2 gangliosidoses are a group of autosomal-recessive lysosomal storage disorders. These diseases result from a deficiency of lysosomal enzyme β-hexosaminidase A (HexA), which is responsible for GM2 ganglioside degradation. HexA deficiency causes the accumulation of GM2-gangliosides mainly in the nervous system cells, leading to severe progressive neurodegeneration and neuroinflammation. To date, there is no treatment for these diseases. Cell-mediated gene therapy is considered a promising treatment for GM2 gangliosidoses. This study aimed to evaluate the ability of genetically modified mesenchymal stem cells (MSCs-HEXA-HEXB) to restore HexA deficiency in Tay-Sachs disease patient cells, as well as to analyze the functionality and biodistribution of MSCs in vivo. The effectiveness of HexA deficiency cross-correction was shown in mutant MSCs upon interaction with MSCs-HEXA-HEXB. The results also showed that the MSCs-HEXA-HEXB express the functionally active HexA enzyme, detectable in vivo, and intravenous injection of the cells does not cause an immune response in animals. These data suggest that genetically modified mesenchymal stem cells have the potentials to treat GM2 gangliosidoses.
PubMed: 37488869
DOI: 10.4103/1673-5374.375328 -
Annals of Clinical and Translational... Jan 2024Late-onset GM2 gangliosidosis (LOGG) subtypes late-onset Tay-Sachs (LOTS) and Sandhoff disease (LOSD) are ultra-rare neurodegenerative lysosomal storage disorders... (Review)
Review
OBJECTIVE
Late-onset GM2 gangliosidosis (LOGG) subtypes late-onset Tay-Sachs (LOTS) and Sandhoff disease (LOSD) are ultra-rare neurodegenerative lysosomal storage disorders presenting with weakness, ataxia, and neuropsychiatric symptoms. Previous studies considered LOTS and LOSD clinically indistinguishable; recent studies have challenged this. We performed a scoping review to ascertain whether imaging and clinical features may differentiate these diseases.
METHODS
We examined MEDLINE/non-MEDLINE databases up to May 2022. Articles reporting brain imaging findings in genetically/enzymatically confirmed LOGG, symptom onset at age ≥ 10 years (or evaluated at least once ≥18 years) were included, yielding 170 LOGG patients (LOTS = 127, LOSD = 43) across 68 papers. We compared LOTS versus LOSD and performed regression analyses. Results were corrected for multiple comparisons.
RESULTS
Age of onset was lower in LOTS versus LOSD (17.9 ± 8.2 vs. 23.9 ± 14.4 years, p = 0.017), although disease duration was similar (p = 0.34). LOTS more commonly had psychosis/bipolar symptoms (35.0% vs. 9.30%, p = 0.011) but less frequent swallowing problems (4.10% vs. 18.60%, p = 0.041). Cerebellar atrophy was more common in LOTS (89.0%) versus LOSD (60.5%), p < 0.0001, with more severe atrophy in LOTS (p = 0.0005). Brainstem atrophy was documented only in LOTS (14.2%). Independent predictors of LOTS versus LOSD (odds ratio [95% confidence interval]) included the presence of psychosis/bipolar symptoms (4.95 [1.59-19.52], p = 0.011), no swallowing symptoms (0.16 [0.036-0.64], p = 0.011), and cerebellar atrophy (5.81 [2.10-17.08], p = 0.0009). Lower age of onset (0.96 [0.93-1.00], p = 0.075) and tremor (2.50 [0.94-7.43], p = 0.078) were marginally statistically significant but felt relevant to include in the model.
INTERPRETATION
These data suggest significant differences in symptomatology, disease course, and imaging findings between LOTS and LOSD.
Topics: Humans; Child; Psychotic Disorders; Disease Progression; Atrophy; Neurodegenerative Diseases; Gangliosidoses, GM2
PubMed: 38009419
DOI: 10.1002/acn3.51947