Parkinsonism in type 1 Gaucher's disease

Frequency of Hereditary and GBA1-Related Parkinsonism in Latin America: A Systematic Review and Meta-Analysis

BACKGROUND

Identifying hereditary parkinsonism is valuable for diagnosis, genetic counseling, patient prioritization in trials, and studying the disease for personalized therapies. However, most studies were conducted in Europeans, and limited data exist on admixed populations like those from Latin America.

OBJECTIVES

This study aims to assess the frequency and distribution of genetic parkinsonism in Latin America.

METHODS

We conducted a systematic review and meta-analysis of the frequency of parkinsonian syndromes associated with genetic pathogenic variants in Latin America. We defined hereditary parkinsonism as those caused by the genes outlined by the MDS Nomenclature of Genetic Movement Disorders and heterozygous carriers of GBA1 pathogenic variants. A systematic search was conducted in PubMed, Web of Science, Embase, and LILACS in August 2022. Researchers reviewed titles and abstracts, and disagreements were resolved by a third researcher. After this screening, five researchers reanalyzed the selection criteria and extracted information based on the full paper. The frequency for each parkinsonism-related gene was determined by the presence of pathogenic/likely pathogenic variants among screened patients. Cochran's Q and I2 tests were used to quantify heterogeneity. Meta-regression, publication bias tests, and sensitivity analysis regarding study quality were also used for LRRK2-, PRKN-, and GBA1-related papers.

RESULTS

We included 73 studies involving 3014 screened studies from 16 countries. Among 7668 Latin American patients, pathogenic variants were found in 19 different genes. The frequency of the pathogenic variants in LRRK2 was 1.38% (95% confidence interval [CI]: 0.52-2.57), PRKN was 1.16% (95% CI: 0.08-3.05), and GBA1 was 4.17% (95% CI: 2.57-6.08). For all meta-analysis, heterogeneity was high and publication bias tests were negative, except for PRKN, which was contradictory. Information on the number of pathogenic variants in the other genes is further presented in the text.

CONCLUSIONS

This study provides insights into hereditary and GBA1-related parkinsonism in Latin America. Lower GBA1 frequencies compared to European/North American cohorts may result from limited access to gene sequencing. Further research is vital for regional prevalence understanding, enabling personalized care and therapies. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Generation of three human induced pluripotent stem cell (hiPSC) lines derived from one Gaucher disease patient with Parkinson's disease and two unrelated Parkinson's disease patients with GBA mutations

We describe the generation and characterization of hiPSC lines of one type 1-Gaucher disease patient with Parkinson's disease and two unrelated Parkinson's disease patients heterozygous for GBA mutations. Human iPSCs were derived from lymphocytes reprogrammed with Sendai virus carrying the reprogramming factors OCT3/4, SOX2, KLF4 and MYC. The hiPSC lines were characterized according to established criteria, and retained the original GBA mutations found in the respective patients.

Unfolded protein response in Gaucher disease: from human to Drosophila

Background

In Gaucher disease (GD), resulting from mutations in the GBA gene, mutant β-glucocerebrosidase (GCase) molecules are recognized as misfolded in the endoplasmic reticulum (ER). They are retrotranslocated to the cytoplasm, where they are ubiquitinated and undergo proteasomal degradation in a process known as the ER Associated Degradation (ERAD). We have shown in the past that the degree of ERAD of mutant GCase correlates with GD severity.

Persistent presence of mutant, misfolded protein molecules in the ER leads to ER stress and evokes the unfolded protein response (UPR).

Methods

We investigated the presence of UPR in several GD models, using molecular and behavioral assays.

Results

Our results show the existence of UPR in skin fibroblasts from GD patients and carriers of GD mutations. We could recapitulate UPR in two different Drosophila models for carriers of GD mutations: flies heterozygous for the endogenous mutant GBA orthologs and flies expressing the human N370S or L444P mutant GCase variants. We encountered early death in both fly models, indicating the deleterious effect of mutant GCase during development. The double heterozygous flies, and the transgenic flies, expressing mutant GCase in dopaminergic/serotonergic cells developed locomotion deficit.

Conclusion

Our results strongly suggest that mutant GCase induces the UPR in GD patients as well as in carriers of GD mutations and leads to development of locomotion deficit in flies heterozygous for GD mutations.

Adult Gaucher disease in southern Tunisia: report of three cases

Background

Gaucher disease (GD) is the most frequent lysosomal storage disorder; type 1 is by far the most common form. It is characterized by variability in age of onset, clinical signs and progression. It is usually diagnosed in the first or second decade of life with the appearance of bone pains, splenomegaly and thrombocytopenia, but the disease may be diagnosed at any age between 1 and 73 years. In the present study, we report 3 cases with late onset of GD in whom the disease was a surprise finding including one patient with Parkinson disease. This late onset is described as an adult form of Gaucher disease.

Findings

Molecular investigation showed mutational homogeneity in Tunisian adult patients suffering from GD. Indeed, all patients carry the p.N370S mutation: two patients at a homozygous state and one patient at compound heterozygous state.

Conclusion

The p.N370S mutation presents a large variability in the onset of the disease and its clinical manifestation supporting the view that GD should be considered as a continuum phenotype rather than a predefined classification.

The enigma of the E326K mutation in acid β-glucocerebrosidase

A large number of mutations, and several polymorphisms, have been characterized in the GBA gene, encoding the lysosomal enzyme glucocerebrosidase, the activity of which is impaired in Gaucher disease. In this communication we summarize published and new data concerning biochemical characterization of the E326K amino acid change (1093G>A in the GBA1 cDNA) in tissue culture and its association with Parkinson disease, suggesting it is a disease causing mutation and not merely a polymorphism in the GBA gene.

Parkinsonism in Gaucher's disease type 1: ten new cases and a review of the literature

Parkinsonism has been described in patients with Gaucher's disease (GD). We reviewed the 10 cases of patients with both parkinsonism and GD recorded in the French national GD registry, as well as 49 previously published cases. Relative to the general population, parkinsonism in GD patients (1) was more frequent, (2) occurred at an earlier age, (3) responded less well to levodopa, and (4) was more frequently associated with signs of cortical dysfunction. Enzyme replacement therapy (ERT) and substrate reduction therapy (SRT) were ineffective on GD-associated parkinsonism, suggesting that parkinsonism itself is not an indication for ERT or SRT in this setting.

'Non-neuronopathic' Gaucher disease reconsidered. Prevalence of neurological manifestations in a Dutch cohort of type I Gaucher disease patients and a systematic review of the literature

Gaucher disease is a lysosomal storage disorder, which is classically divided into three types. Type I Gaucher disease is differentiated from types II and III disease by the absence of nervous system involvement. However, an increasing number of reports has emerged on neurological manifestations in patients with type I Gaucher disease. Whether a strict division in three different phenotypes is still valid has been the subject of debate. The main objective of this study was to provide scientific arguments whether a distinction between type I (non-neuronopathic) and types II and III (neuronopathic) Gaucher disease should be maintained. We investigated retrospectively a large Dutch cohort of type I Gaucher disease patients for the prevalence of neurological manifestations and provide an overview of the literature on this topic. A diagnosis of a neurological disease was made 34 times in 75 patients. Forty-five patients reported at least one neurological symptom during the median follow-up time of 11 years. The literature search revealed 86 studies in which type I Gaucher disease patients or carriers of a glucocerebrosidase mutation were described with a neurological disease or a condition which is known to be associated with neurological disease. In conclusion, the term non-neuronopathic Gaucher disease does not seem to be an appropriate characterization of type I Gaucher disease. However, the neurological signs and symptoms in type I Gaucher disease are of a totally different kind from and, in the majority of cases, of much less severity than the signs and symptoms associated with types II and III disease Therefore, type I disease should be classified as a separate phenotype.

Association between Parkinson's disease and glucocerebrosidase mutations in Brazil

OBJECTIVE

To evaluate the association between parkinsonism and mutations in the glucocerebrosidase gene (GBA) in Brazilian patients.

METHODS

We searched for three GBA common mutations (N370S, L444P and G377S) in 65 Brazilian patients affected by PD with disease onset before the age of 55 and compared the results to 267 age- and sex-matched controls.

RESULTS

GBA mutations were detected at a significantly higher frequency among Parkinson's disease patients (2/65=3%), when compared to the control group (0/267): P=0.0379.

CONCLUSION

These results provide further evidence for GBA mutations being a possible hereditary risk factor for PD.