Neuronopathic Gaucher disease: Rare in the West, common in the East.

Gaucher disease (GD) stands as one of the most prevalent lysosomal disorders, yet neuronopathic GD (nGD) is an uncommon subset characterized by a wide array of clinical manifestations that complicate diagnosis, particularly when neurological symptoms are understated. nGD may manifest as the acute neuronopathic type, or GD type 2 (GD2), either prenatally or within the first weeks to months of life, whereas GD type 3 (GD3) symptoms may emerge at any point during childhood or occasionally in adolescence. The clinical presentation encompasses severe systemic involvement to mild visceral disease, often coupled with a spectrum of progressive neurological signs and symptoms such as cognitive impairment, ataxia, seizures, myoclonus, varying degrees of brainstem dysfunction presenting with stridor, apneic episodes, and/or impaired swallowing. This manuscript aims to provide a comprehensive review of the incidence, distinctive presentations, and diverse clinical phenotypes of nGD across various countries and regions. It will explore the natural history of the neurodegenerative process in GD, shedding light on its various manifestations during infancy and childhood, and offer insights into the diagnostic journey, the challenges faced in the clinical management, and current and investigative therapeutic approaches for GD's neurological variants.

Cerebrospinal fluid lysosomal enzymes and alpha-synuclein in Parkinson's disease.

To assess the discriminating power of multiple cerebrospinal fluid (CSF) biomarkers for Parkinson's disease (PD), we measured several proteins playing an important role in the disease pathogenesis. The activities of ß-glucocerebrosidase and other lysosomal enzymes, together with total and oligomeric α-synuclein, and total and phosphorylated tau, were thus assessed in CSF of 71 PD patients and compared to 45 neurological controls. Activities of ß-glucocerebrosidase, ß-mannosidase, ß-hexosaminidase, and ß-galactosidase were measured with established enzymatic assays, while α-synuclein and tau biomarkers were evaluated with immunoassays. A subset of PD patients (n = 44) was also screened for mutations in the ß-glucocerebrosidase-encoding gene (GBA1). In the PD group, ß-glucocerebrosidase activity was reduced (P < 0.05) and patients at earlier stages showed lower enzymatic activity (P < 0.05); conversely, ß-hexosaminidase activity was significantly increased (P < 0.05). Eight PD patients (18%) presented GBA1 sequence variations; 3 of them were heterozygous for the N370S mutation. Levels of total α-synuclein were significantly reduced (P < 0.05) in PD, in contrast to increased levels of α-synuclein oligomers, with a higher oligomeric/total α-synuclein ratio in PD patients when compared with controls (P < 0.001). A combination of ß-glucocerebrosidase activity, oligomeric/total α-synuclein ratio, and age gave the best performance in discriminating PD from neurological controls (sensitivity 82%; specificity 71%, area under the receiver operating characteristic curve = 0.87). These results demonstrate the possibility of detecting lysosomal dysfunction in CSF and further support the need to combine different biomarkers for improving the diagnostic accuracy of PD.

Chronic neuronopathic type of Gaucher's disease with progressive myoclonic epilepsy in the absence of visceromegaly and bone involvement.

INTRODUCTION: Gaucher's disease is a lysosomal storage disorder caused by the deficiency of glucocerebrosidase. Gaucher's disease has three clinical types: non-neuronopathic (Type 1), Acute Neuropathic (Type 2) and chronic neuronopathic (Type 3). The chronic neuronopathic (Type 3) is characterised by a variety of disease variants with onset in childhood with hepatomegaly, skeletal lesions and later slow horizontal saccades, treatment-resistant generalised tonic-clonic and myoclonic seizures, dementia, progressive spasticity, cognitive deterioration, ataxia and death in the second or third decade of life. CASE PRESENTATION: We describe a case of a 17-year-old girl who was born normally but subsequently developed treatment-refractory seizures at the age of nine with myoclonus, oculomotor apraxia, ataxia and cognitive decline. Enzyme activity of beta-glucocerebrosidase was found to be low without visceromegaly or bone involvement. CONCLUSION: Screening for lysosomal enzyme activity should be done in patients exhibiting features suggestive of progressive myoclonic epilepsy.

Pediatric Gaucher Disease Type 3 Presenting with Oculomotor Apraxia: A Case Report.

We report on a 4-year-old boy affected by Gaucher disease (GD) type 3, who presented with splenomegaly and a history of oculomotor apraxia. GD is a rare lysosomal storage disorder caused by glucocerebrosidase deficiency with multi-organ involvement. Besides common clinical features such as hepatosplenomegaly and skeletal involvement, less frequent neurological symptoms, such as oculomotor apraxia, are indicative of neuronopathic forms of the disease, namely GD type 3, to be confirmed both by enzyme activity and genetic testing. Overall, GD management requires a multidisciplinary approach involving metabolic pediatricians, neurologists, psychologists, and geneticists, and currently relies on early enzyme replacement therapy. Although enzyme replacement therapy has proved to be effective in improving systemic signs and symptoms, it is unable to alleviate neurological complications once these have occurred, as it does not pass across the blood-brain barrier. Neurological improvements may occur through indirect mechanisms. Thus, our case report aims to highlight the importance of considering GD in the differential diagnosis of pediatric patients presenting with splenomegaly associated with neurological manifestations, as early intervention may significantly modify the disease progression and prevent further irreversible complications.

Mutational Analysis and Genotype Investigation of Less Known Gaucher Mutations through Haplotype Analysis in Iranian Gaucher Patients.

Gaucher's disease (GD) is the most frequent lysosomal storage disorder resulting from a deficiency of the enzyme glucocerebrosidase (GBA) which causes the accumulation of glucocerebroside. More than 500 mutations have been reported on the GBA gene so far. In this study, we aimed to investigate more on the genotype of less known mutations through haplotype analysis to explain their disease-causing inheritance. Eight patients and three carriers from nine different families were enrolled in the study. DNA sequencing of all GBA gene's exons was performed and pathogenicity of the mutations was investigated. Using GBA gene-linked STR markers, allele segregations were determined in some families. A total of six different mutations were determined. Five and three patients were identified to carry mutations in homozygous and compound heterozygote patterns respectively, three participants also were identified as carriers. The most prevalent mutations were c.1448 T>C and RecNcil, however, three less common mutations were identified (i.e., c.1223 C>T, c.1315 A>G, and c.1214 G>C). In conclusion, we evaluated six different mutations in Iranian patients and elucidated the inheritance of the three less-known mutations by linkage analysis.

Transcriptome deregulation of peripheral monocytes and whole blood in GBA-related Parkinson's disease.

BACKGROUND: Genetic mutations in beta-glucocerebrosidase (GBA) represent the major genetic risk factor for Parkinson's disease (PD). GBA participates in both the endo-lysosomal pathway and the immune response, two important mechanisms involved in the pathogenesis of PD. However, modifiers of GBA penetrance have not yet been fully elucidated. METHODS: We characterized the transcriptomic profiles of circulating monocytes in a population of patients with PD and healthy controls (CTRL) with and without GBA variants (n = 23 PD/GBA, 13 CTRL/GBA, 56 PD, 66 CTRL) and whole blood (n = 616 PD, 362 CTRL, 127 PD/GBA, 165 CTRL/GBA). Differential expression analysis, pathway enrichment analysis, and outlier detection were performed. Ultrastructural characterization of isolated CD14+ monocytes in the four groups was also performed through electron microscopy. RESULTS: We observed hundreds of differentially expressed genes and dysregulated pathways when comparing manifesting and non-manifesting GBA mutation carriers. Specifically, when compared to idiopathic PD, PD/GBA showed dysregulation in genes involved in alpha-synuclein degradation, aging and amyloid processing. Gene-based outlier analysis confirmed the involvement of lysosomal, membrane trafficking, and mitochondrial processing in manifesting compared to non-manifesting GBA-carriers, as also observed at the ultrastructural levels. Transcriptomic results were only partially replicated in an independent cohort of whole blood samples, suggesting cell-type specific changes. CONCLUSIONS: Overall, our transcriptomic analysis of primary monocytes identified gene targets and biological processes that can help in understanding the pathogenic mechanisms associated with GBA mutations in the context of PD.

Rescue of α-synuclein aggregation in Parkinson's patient neurons by synergistic enhancement of ER proteostasis and protein trafficking.

Neurodegenerative disorders are characterized by a collapse in proteostasis, as shown by the accumulation of insoluble protein aggregates in the brain. Proteostasis involves a balance of protein synthesis, folding, trafficking, and degradation, but how aggregates perturb these pathways is unknown. Using Parkinson's disease (PD) patient midbrain cultures, we find that aggregated α-synuclein induces endoplasmic reticulum (ER) fragmentation and compromises ER protein folding capacity, leading to misfolding and aggregation of immature lysosomal ß-glucocerebrosidase. Despite this, PD neurons fail to initiate the unfolded protein response, indicating perturbations in sensing or transducing protein misfolding signals in the ER. Small molecule enhancement of ER proteostasis machinery promotes ß-glucocerebrosidase solubility, while simultaneous enhancement of trafficking improves ER morphology, lysosomal function, and reduces α-synuclein. Our studies suggest that aggregated α-synuclein perturbs the ability of neurons to respond to misfolded proteins in the ER, and that synergistic enhancement of multiple proteostasis branches may provide therapeutic benefit in PD.

Molecular regulations and therapeutic targets of Gaucher disease.

Gaucher disease (GD) is the most common lysosomal storage disease caused by deficiency of beta-glucocerebrosidase (GCase) resulting in lysosomal accumulation of its glycolipid substrate glucosylceramide. The activity of GCase depends on many factors such as proper folding and lysosomal localization, which are influenced by mutations in GCase encoding gene, and regulated by various GCase-binding partners including Saposin C, progranulin and heat shock proteins. In addition, proinflammatory molecules also contribute to pathogenicity of GD. In this review, we summarize the molecules that are known to be important for the pathogenesis of GD, particularly those modulating GCase lysosomal appearance and activity. In addition, small molecules that inhibit inflammatory mediators, calcium ion channels and other factors associated with GD are also described. Discovery and characterization of novel molecules that impact GD are not only important for deciphering the pathogenic mechanisms of the disease, but they also provide new targets for drug development to treat the disease.

A pilot screening of high-risk Gaucher disease children using dried blood spot methods in Shandong province of China.

BACKGROUND: The study aim was to verify the feasibility of a diagnostic algorithm with the evaluation of beta glucocerebrosidase (GBA) activity on dried blood spots (DBS) in screening high-risk Gaucher disease (GD) children in China, and to investigate the GD prevalence in this selected population. METHODS: Children were recruited from 20 departments of pediatrics or children's hospitals in Shandong Province, China, due to splenomegaly and/or thrombocytopenia associated with one or more of the following creteria: anemia, history of bone pain, monoclonal gammopathy of unknown significance (MGUS), polyclonal gammopathy and splenectomy. GBA activity on DBS was tested, and patients with DBS GBA activity under 30 nmol/h.ml were recalled to assess enzyme assay with gold standard and molecular GBA gene analysis on leukocytes. RESULTS: A total of 73 children (47 boys and 26 girls) were enrolled in this study. GBA activity DBS < 30 nmol/h.ml was found in 18 (23.7%) children among which four (three boys and one girl) were diagnosed as GD with a median age 1.5 years, and the prevalence in this pediatric population was 5.5% (1.5%~ 13.4%). Three new mutations of GBA found in the four GD patients, L264I, A100Cfs*7 and D399E, have not been reported before. CONCLUSIONS: With evaluation of GBA activity on DBS as a preliminary screening method, the diagnostic algorithm used in this study is appropriate to make early diagnosis for GD patients with mild symptoms or atypical symptoms and avoid diagnosis delay. TRIAL REGISTRATION: Not applicable.

Enfermedad de Gaucher, diagnostico en el embarazo, reporte de caso y consideraciones de su tratamiento en Colombia / Gaucher disease, diagnosis in pregnancy, report case study and considerations of its treatment in Colombia

RESUMEN Introducción y Objetivo: La enfermedad de Gaucher es una condición autosómica recesiva de baja prevalencia, de difícil diagnóstico y manejo, especialmente en embarazo. Reportamos una gestante con enfermedad de Gaucher manejada desde la semana 15,3 hasta el término del embarazo con Taliglucerasa en la Unidad de Alta Complejidad Obstétrica, en la Fundación Valle del Lili en Cali, Colombia. Métodos: Reporte de caso de gestante con diagnóstico de enfermedad de Gaucher diagnosticada durante el embarazo, con exacerbación de síntomas, quien presento severa pancitopenia y esplenomegalia. Resultados: El manejo medico interdiscilplinario permitió el control del severo deterioro clínico de la paciente durante el parto, presentó hemorragia postparto con choque hipovolémico, con adecuada respuesta al manejo médico. La madre y el neonato fueron dados de alta sin otras complicaciones asociadas. Conclusión: El manejo interdisciplinario es indispensable en gestantes con esta entidad para lograr buenos resultados maternos y perinatales.

ABSTRACT Introduction and Objective: Gaucher disease is a low prevalence autosomal recessive condition, difficult to diagnose and manage especially during pregnancy. We reported a pregnant woman with Gaucher disease managed with Taliglucerase in a critical care obstetric unit from week 15.3 until the end of her pregnancy, at the Fundación Valle del Lili, Cali, Colombia. Methods: A case report of a pregnant woman diagnosed during her pregnancy with Gaucher disease, who presented severe pancytopenia and splenomegaly. Results: The interdisciplinary medical management allowed the control of the severe clinical deterioration of the patient. During the delivery, she presented postpartum hemorrhage with hypovolemic shock, which resolved with medical management. The mother and the newborn were discharged without other associated complications. Conclusion: Interdisciplinary management is essential for handling a critically ill obstetric patient with Gaucher disease, and to achieve good maternal and perinatal outcomes.

Increased lysosomal biogenesis in activated microglia and exacerbated neuronal damage after traumatic brain injury in progranulin-deficient mice.

Progranulin (PGRN) is known to play a role in the pathogenesis of neurodegenerative diseases. Recently, it has been demonstrated that patients with the homozygous mutation in the GRN gene present with neuronal ceroid lipofuscinosis, and there is growing evidence that PGRN is related to lysosomal function. In the present study, we investigated the possible role of PGRN in the lysosomes of activated microglia in the cerebral cortex after traumatic brain injury (TBI). We showed that the mouse GRN gene has two possible coordinated lysosomal expression and regulation (CLEAR) sequences that bind to transcription factor EB (TFEB), a master regulator of lysosomal genes. PGRN was colocalized with Lamp1, a lysosomal marker, and Lamp1-positive areas in GRN-deficient (KO) mice were significantly expanded compared with wild-type (WT) mice after TBI. Expression of all the lysosome-related genes examined in KO mice was significantly higher than that in WT mice. The number of activated microglia with TFEB localized to the nucleus was also significantly increased in KO as compared with WT mice. Since the TFEB translocation is regulated by the mammalian target of rapamycin complex 1 (mTORC1) activity in the lysosome, we compared ribosomal S6 kinase 1 (S6K1) phosphorylation that reflects mTORC1 activity. S6K1 phosphorylation in KO mice was significantly lower than that in WT mice. In addition, the number of nissl-positive and fluoro-jade B-positive cells around the injury was significantly decreased and increased, respectively, in KO as compared with WT mice. These results suggest that PGRN localized in the lysosome is involved in the activation of mTORC1, and its deficiency leads to increased TFEB nuclear translocation with a resultant increase in lysosomal biogenesis in activated microglia and exacerbated neuronal damage in the cerebral cortex after TBI.