Global Incidence and Prevalence of Gaucher Disease: A Targeted Literature Review

A 10-year follow-up of high-dose ambroxol treatment combined with enzyme replacement therapy for neuropathic Gaucher disease

High-dose ambroxol therapy combined with ERT in patients with neuropathic Gaucher disease.

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.

A review of type 3 Gaucher disease: unique neurological manifestations and advances in treatment

Gaucher disease (GD) is a rare lysosomal storage disease that is caused by mutations in the GBA gene. It is classified into three main phenotypes according to the patient's clinical presentation. Of these, chronic neuronopathic GD (GD3) is characterized by progressive neurological damage. Understanding the unique neurological manifestations of GD3 has important diagnostic and therapeutic implications. Our article summarizes the neurological symptoms specific to GD3 and related therapeutic advances, and it highlights the relevance of the gene to clinical symptoms, so as to provide a reference for the diagnosis and treatment of GD3.

Assessing the diagnostic utility of the Gaucher Earlier Diagnosis Consensus (GED-C) scoring system using real-world data

BACKGROUND

Gaucher disease (GD) is a rare autosomal recessive condition associated with clinical features such as splenomegaly, hepatomegaly, anemia, thrombocytopenia, and bone abnormalities. Three clinical forms of GD have been defined based on the absence (type 1, GD1) or presence (types 2 and 3) of neurological signs. Early diagnosis can reduce the likelihood of severe, often irreversible complications. The aim of this study was to validate the ability of factors from the Gaucher Earlier Diagnosis Consensus (GED-C) scoring system to discriminate between patients with GD1 and controls using real-world data from electronic patient medical records from Maccabi Healthcare Services, Israel's second-largest state-mandated healthcare provider.

METHODS

We applied the GED-C scoring system to 265 confirmed cases of GD and 3445 non-GD controls matched for year of birth, sex, and socioeconomic status identified from 1998 to 2022. The analyses were based on two databases: (1) all available data and (2) all data except free-text notes. Features from the GED-C scoring system applicable to GD1 were extracted for each individual. Patients and controls were compared for the proportion of the specific features and overall GED-C scores. Decision tree and random forest models were trained to identify the main features distinguishing GD from non-GD controls.

RESULTS

The GED-C scoring distinguished individuals with GD from controls using both databases. Decision tree models for the databases showed good accuracy (0.96 [95% CI 0.95-0.97] for Database 1; 0.95 [95% CI 0.94-0.96] for Database 2), high specificity (0.99 [95% CI 0.99-1]) for Database 1; 1.0 [95% CI 0.99-1] for Database 2), but relatively low sensitivity (0.53 [95% CI 0.46-0.59] for Database 1; 0.32 [95% CI 0.25-0.38]) for Database 2). The clinical features of splenomegaly, thrombocytopenia (< 50 × 109/L), and hyperferritinemia (300-1000 ng/mL) were found to be the three most accurate classifiers of GD in both databases.

CONCLUSION

In this analysis of real-world patient data, certain individual features of the GED-C score discriminate more successfully between patients with GD and controls than the overall score. An enhanced diagnostic model may lead to earlier, reliable diagnoses of Gaucher disease, aiming to minimize the severe complications associated with this disease.

Blood cytopenias as manifestations of inherited metabolic diseases: a narrative review

Inherited Metabolic Diseases (IMD) encompass a diverse group of rare genetic conditions that, despite their individual rarity, collectively affect a substantial proportion, estimated at as much as 1 in 784 live births. Among their wide-ranging clinical manifestations, cytopenia stands out as a prominent feature. Consequently, IMD should be considered a potential diagnosis when evaluating patients presenting with cytopenia. However, it is essential to note that the existing scientific literature pertaining to the link between IMD and cytopenia is limited, primarily comprising case reports and case series. This paucity of data may contribute to the inadequate recognition of the association between IMD and cytopenia, potentially leading to underdiagnosis. In this review, we synthesize our findings from a literature analysis along with our clinical expertise to offer a comprehensive insight into the clinical presentation of IMD cases associated with cytopenia. Furthermore, we introduce a structured diagnostic approach underpinned by decision-making algorithms, with the aim of enhancing the early identification and management of IMD-related cytopenia.

Exploring the efficacy and safety of Ambroxol in Gaucher disease: an overview of clinical studies

Gaucher disease (GD) is mainly caused by glucocerebrosidase (GCase) enzyme deficiency due to genetic variations in the GBA1 gene leading to the toxic accumulation of sphingolipids in various organs, which causes symptoms such as anemia, thrombocytopenia, hepatosplenomegaly, and neurological manifestations. GD is clinically classified into the non-neuronopathic type 1, and the acute and chronic neuronopathic forms, types 2 and 3, respectively. In addition to the current approved GD medications, the repurposing of Ambroxol (ABX) has emerged as a prospective enzyme enhancement therapy option showing its potential to enhance mutated GCase activity and reduce glucosylceramide accumulation in GD-affected tissues of different GBA1 genotypes. The variability in response to ABX varies across different variants, highlighting the diversity in patients' therapeutic outcomes. Its oral availability and safety profile make it an attractive option, particularly for patients with neurological manifestations. Clinical trials are essential to explore further ABX's potential as a therapeutic medication for GD to encourage pharmaceutical companies' investment in its development. This review highlights the potential of ABX as a pharmacological chaperone therapy for GD and stresses the importance of addressing response variability in clinical studies to improve the management of this rare and complex disorder.

Identification of GM1-Ganglioside Secondary Accumulation in Fibroblasts from Neuropathic Gaucher Patients and Effect of a Trivalent Trihydroxypiperidine Iminosugar Compound on Its Storage Reduction

Gaucher disease (GD) is a rare genetic metabolic disorder characterized by a dysfunction of the lysosomal glycoside hydrolase glucocerebrosidase (GCase) due to mutations in the gene GBA1, leading to the cellular accumulation of glucosylceramide (GlcCer). While most of the current research focuses on the primary accumulated material, lesser attention has been paid to secondary storage materials and their reciprocal intertwining. By using a novel approach based on flow cytometry and fluorescent labelling, we monitored changes in storage materials directly in fibroblasts derived from GD patients carrying N370S/RecNcil and homozygous L444P or R131C mutations with respect to wild type. In L444P and R131C fibroblasts, we detected not only the primary accumulation of GlcCer accumulation but also a considerable secondary increase in GM1 storage, comparable with the one observed in infantile patients affected by GM1 gangliosidosis. In addition, the ability of a trivalent trihydroxypiperidine iminosugar compound (CV82), which previously showed good pharmacological chaperone activity on GCase enzyme, to reduce the levels of storage materials in L444P and R131C fibroblasts was tested. Interestingly, treatment with different concentrations of CV82 led to a significant reduction in GM1 accumulation only in L444P fibroblasts, without significantly affecting GlcCer levels. The compound CV82 was selective against the GCase enzyme with respect to the β-Galactosidase enzyme, which was responsible for the catabolism of GM1 ganglioside. The reduction in GM1-ganglioside level cannot be therefore ascribed to a direct action of CV82 on β-Galactosidase enzyme, suggesting that GM1 decrease is rather related to other unknown mechanisms that follow the direct action of CV82 on GCase. In conclusion, this work indicates that the tracking of secondary storages can represent a key step for a better understanding of the pathways involved in the severity of GD, also underlying the importance of developing drugs able to reduce both primary and secondary storage-material accumulations in GD.

Uncovering the Challenges of Rare Diseases: Insights From a Retrospective Cross-Sectional Study in Albania (2005-2022)

BACKGROUND

Diagnosing and treating rare diseases pose significant challenges within global healthcare systems due to their low prevalence and varying criteria for defining them. In Albania, the absence of a dedicated registry for rare diseases exacerbates these challenges. Recognising this gap, a retrospective cross-sectional study was conducted from January 2005 to December 2022 to analyse the incidence and prevalence of rare haematologic diseases in the country, diagnosed in the Hematology Service at the University Hospital Centre "Mother Teresa," which is the sole diagnostic center for blood diseases in Albania. This study aims to provide insights into the frequency of these diseases within the adult Albanian population and seeks to underscore the critical need for improved data collection and research in this field of healthcare.

OBJECTIVE

The primary objective of this study is to assess the incidence and prevalence of rare hematologic diseases diagnosed at the Hematology Service of the University Hospital Centre "Mother Teresa" in Albania from January 2005 to December 2022.

MATERIALS AND METHODS

This retrospective cross-sectional study employed a descriptive study design, focusing on the analysis of rare hematologic disease incidence and prevalence. The study was conducted exclusively at the University Hospital Centre "Mother Teresa" in Albania, the primary diagnostic center for blood-related disorders in the country. Data collection spanned a period of 18 years, from January 2005 to December 2022, encompassing patient records. Inclusion criteria encompassed adult patients aged 15 years and older who had received diagnoses of rare hematologic diseases during the specified timeframe, without specific operational definitions applied. Non-probability convenience sampling was used, including all eligible cases identified within the study's timeframe, obviating the need for formal sample size calculation. Data were extracted from the records of the Hematology Service at the University Hospital Centre "Mother Teresa," primarily using medical records containing essential patient information. Data analysis utilised software such as EXCEL 16.0 and SPSS (v. 25.0), applying descriptive statistical methods, including frequencies and percentages, to assess the incidence and prevalence of rare hematologic diseases. The study's findings were summarised and presented in a tabular format to provide a clear and concise overview of the results.

RESULTS

Our study identified 64 cases of rare hematologic diseases among adults. Notably, primary myelofibrosis (MF) exhibited the highest incidence and prevalence rate, followed by Waldenström macroglobulinemia (WM) and Gaucher disease (GD) emerging as the most prevalent diagnoses after MF, with 16 and 10 cases, respectively. Several ultra-rare diseases, such as Fanconi anemia and chronic eosinophilic leukemia, were also detected, indicating a significant disease burden, while diseases such as Factor X deficiency and Niemann-Pick disease type C were exceptionally rare.

CONCLUSION

Diagnosing and treating rare diseases remain formidable challenges in healthcare systems worldwide. This study underscores the need for enhanced awareness, research, and the pressing need for dedicated registries, collaborative research initiatives, and heightened attention to these conditions to enhance our understanding and management of rare hematological diseases, particularly within the Albanian healthcare context.

Cancer Risk in Patients with Gaucher Disease Using Real-World Data

The association between GD and cancer has been uncertain due to ascertainment bias in previously published studies. We analyzed cancer incidence using the Maccabi Healthcare Service (MHS) electronic health records among 264 patients with GD compared to 3440 matched controls. We ascertained cancers diagnosed before and after the index date (i.e., the first documentation of GD in cases and the corresponding date for controls). Before the index date, cancers were diagnosed in 18 individuals, with 11 (4.2%) in the GD group and 7 (0.2%) in the control group. After the index date, cancers were diagnosed in 57 individuals, with 20 (7.9%) in the GD group and 37 (1.1%) in the control group, with a median follow-up of almost 13 years in both groups. The most common cancers diagnosed in GD were non-melanoma skin cancer (NMSC) and hematological malignancies, with a clustering of diagnoses around the time of GD diagnosis. The incidence of cancers (excluding MNSC) was 4.1 (95% CI 2.2-7.1) and 0.7 (95% CI 0.4-0.9) per 1000 patient-years in the GD and control groups, respectively, with an incidence rate ratio of 6.37 (95% CI 3-12.7). Patients with GD underwent more cancer screening tests than their counterparts in the control group. While our study revealed an increased occurrence of cancers in patients with GD, this finding might be partly attributed to the more rigorous surveillance procedures employed in this patient population.

Effectiveness and Safety of Eliglustat Treatment in Gaucher Disease: Real-life Unicentric Experience

PURPOSE

The therapy and management of Gaucher disease (GD) have radically changed with the use of substrate reduction therapy, of which eliglustat is the most widely known drug, allowing it to overcome the limits of enzyme replacement therapy (ERT). The rarity of GD and the limited use of eliglustat outside clinical trials require further study of its strengths and weaknesses.

METHODS

In this study, we evaluated the effectiveness and safety of eliglustat in a cohort of 12 patients with GD followed up in our center, reporting a reduction in both chitotriosidase (394.3 vs 181.1 nmol/h/mL, P = 0.027) and glucosylsphingosine values (45.1 vs 18.9 ng/mL, P <0.001) after at least 12 months of therapy compared with baseline, regardless of patient demographic characteristics and GD characteristics.

FINDINGS

There were no drug-related serious adverse effects and no drug-related cardiac events. Most adverse events were mild and transient, mainly dyspepsia and abdominal pain. Of interest, we reported an absence of statistical difference in terms of response regarding glucosylsphingosine reduction in relation to naive or prior exposure to ERT (P = 0.296), which was confirmed also when patients were placed in naive and treated groups for <5 vs >5 years (P = 0.667).

IMPLICATIONS

The use of eliglustat immediately after diagnosis may guarantee the best treatment for patients with milder phenotypes or with aggressive disease after an initial stabilization with ERT compared with ERT, which cannot adequately remove the disease burden despite the apparent response, thus potentially reducing future complications caused by substrate deposits.

Noninvasive DBS-Based Approaches to Assist Clinical Diagnosis and Treatment Monitoring of Gaucher Disease

Gaucher disease (GD) is an autosomal recessive inborn error of metabolism, belonging to the group of lysosomal storage diseases (LSDs). GD is caused by a defect in lysosomal glucocerebrosidase, responsible for glucosylceramide breakdown into glucose and ceramide. Because of this dysfunction, glucosylceramide progressively accumulates in the liver, spleen, bone marrow, bones, and in other tissues and organs, also causing anemia, hepatosplenomegaly, thrombocytopenia, and bone symptoms. Depending on neurological symptoms, GD is classified into three main types. Treatment options for LSDs, including enzyme replacement therapy, hematopoietic stem cell transplantation, small molecular weight pharmacologic chaperones, and, for some LSDs, gene therapy, are increasingly available. For this reason, many efforts are aimed at implementing newborn screening for LSDs since early detection accompanied by a prompt intervention has been demonstrated to be essential for reducing morbidity and mortality and for improved clinical outcomes. Herein, we report two siblings of preschool age, presenting with hepatosplenomegaly and thrombocytopenia. The initial suspicion of GD based on the clinical picture was further supported by biochemical confirmation, through newborn screening workflow, including first- and second-level testing on the same dried blood spot samples, and finally by molecular testing.

Incidence of Pulmonary and Respiratory Conditions in Gaucher Disease from 2000 to 2020: A Multi-institutional Cohort Study

BACKGROUND/AIM

Gaucher disease (GD) is a rare lysosomal storage disorder that can involve the lungs and pulmonary vasculature. The long-term effects of GD on respiratory health remain unclear due to limited data on the natural history of this disease. We analyzed electronic health records for 11,004 patients with GD over 10-20 years to determine the incidence of pulmonary hypertension (PH), lung disease, and other respiratory comorbidities and better understand disease course to guide management.

PATIENTS AND METHODS

We conducted a retrospective cohort study using the TriNetX research database of 130 million international patients. The incidence of primary/secondary PH, pulmonary heart disease, interstitial/obstructive/restrictive lung disease, pulmonary hemorrhage, and pulmonary embolism was assessed in patients with GD from 2000-2020.

RESULTS

Incidence rates of all conditions assessed increased from 10 to 20 years of follow-up. Excess risk of PH, lung disease, and pulmonary hemorrhage was significantly higher in GD patients after 20 versus 10 years.

CONCLUSION

Extended follow-up in GD is associated with substantially higher risks of PH, lung disease and other respiratory comorbidities, highlighting the need for close monitoring and early intervention to mitigate long-term pulmonary decline. Improved understanding of mechanisms driving respiratory deterioration can support the development of novel treatments to optimize outcomes in this population at high risk of pulmonary morbidity and mortality.

Gene Therapy of Sphingolipid Metabolic Disorders

Sphingolipidoses are defined as a group of rare hereditary diseases resulting from mutations in the genes encoding lysosomal enzymes. This group of lysosomal storage diseases includes more than 10 genetic disorders, including GM1-gangliosidosis, Tay-Sachs disease, Sandhoff disease, the AB variant of GM2-gangliosidosis, Fabry disease, Gaucher disease, metachromatic leukodystrophy, Krabbe disease, Niemann-Pick disease, Farber disease, etc. Enzyme deficiency results in accumulation of sphingolipids in various cell types, and the nervous system is also usually affected. There are currently no known effective methods for the treatment of sphingolipidoses; however, gene therapy seems to be a promising therapeutic variant for this group of diseases. In this review, we discuss gene therapy approaches for sphingolipidoses that are currently being investigated in clinical trials, among which adeno-associated viral vector-based approaches and transplantation of hematopoietic stem cells genetically modified with lentiviral vectors seem to be the most effective.