High-risk screening for Gaucher disease in patients with neurological symptoms

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.

[Misdiagnosis of Gaucher disease in real life: Retrospective study of the French Gaucher's disease registry]

INTRODUCTION

Gaucher disease is an autosomal recessive genetic disorder. It is caused by a deficiency of the lysosomal enzyme, glucocerebrosidase which leads to an accumulation of glucosylceramide in the macrophages. Splenomegaly, hepatomegaly, cytopenias (anemia, thrombocytopenia) and bone disorders are the main symptoms. The diagnosis is often delayed, leading to unnecessary investigations and treatments, and delaying the specific treatment. The primary objective of our study was to establish, in patients who had a diagnostic delay of more than one year, the reported misdiagnoses before the final diagnosis. The secondary objectives were to investigate the risk factors associated with error and delayed diagnosis.

METHODS

Retrospective study including patients with Gaucher disease from the French Gaucher Disease Registry. Collection of data by a single investigator from a standardized form.

RESULTS

Among 83 patients with a known diagnostic delay, 13 patients (15 %) had one or two misdiagnoses. These included osteo-articular diagnoses (osteomyelitis, osteoarthritis, arthritis, osteochondritis, rheumatic fever, n=8), haematological diagnoses (gestational thrombocytopenia, immunological thrombocytopenia, n=4), infectious diagnoses (visceral leishmaniasis, mononucleosis, n=2) and hemochromatosis. The osteo-articular and infectious diagnoses concerned the child and the adolescent while the haematological diagnoses and the hemochromatosis concerned the adult. No factors were found associated with misdiagnoses. Patients with a diagnostic delay greater than one year were less likely to have hepatosplenomegaly as the first symptom.

CONCLUSION

There is a risk of diagnostic error related to phenotypic heterogeneity and lack of specificity of Gaucher disease symptoms. This study helps to better identify the misdiagnoses associated with Gaucher disease.

Perinatal lethal Gaucher disease: A case report and review of literature

Perinatal lethal Gaucher disease is a very rare variant of type 2 Gaucher disease that occurs in the neonatal period and leads to death in early infancy. The disease is characterized by hydrops fetalis or a collodion baby phenotype accompanied with progressive neurological manifestations, hepatosplenomegaly, thrombocytopenia, anemia, and failure to thrive. We report a case of perinatal lethal Gaucher disease treated with enzyme replacement therapy (ERT) who survived for 9 months and present a literature review of perinatal lethal Gaucher disease cases. The prognosis of perinatal lethal Gaucher disease is poor, and ERT is only effective in visceral manifestation. Therefore, palliative care should be recognized as a treatment option, and ERT employment needs to be discussed in this context.

Newborn screening for Gaucher disease in Japan

Gaucher disease (GD) is an autosomal recessive inborn metabolic disorder caused by a glucocerebrosidase (GCase) defect. GD is classified into three main types depending on accompanying neurological symptoms. Enzyme replacement therapy and substrate reduction therapy are limited in the treatment of neurological symptoms, and using genotype and GCase activity to discriminate between non-neuronopathic and neuronopathic GD may be challenging as the two sometimes phenotypically overlap. The number of patients exhibiting neurological symptoms in Japan is significantly higher than that in Europe and the United States, and newborn screening (NBS) is still not actively performed in Japan. Definitive determination of the actual frequency and proportion of the type of GD from the results of NBS remains inconclusive. We performed NBS for Fabry disease, Pompe disease, and GD, mainly in the Kyushu area in Japan. Herein, we discuss the results of NBS for GD, as well as, the insights gained from following the clinical course of patients diagnosed through NBS. A total of 155,442 newborns were screened using an enzyme activity assay using dried blood spots. We found four newborns showing lower GCase activity and were definitively diagnosed with GD by GBA gene analysis. The frequency of GD diagnosis through NBS was 1 in 77,720 when limited to the probands. This frequency is higher than that previously estimated in Japan. In the future, NBS for GD is expected to be performed in many regions of Japan and contribute to detecting more patients with GD. Early screening and diagnosis may have a very significant impact on the quality of life and potentially longevity in infants with GD.

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Newborn screening (NBS) identified 4 cases of Gaucher disease (GD) with few false positives in Japan.

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The frequency of GD diagnosis through NBS was 1 in 77,720, being higher than the previously estimated.

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Early diagnosis may have a very significant impact on the quality of life and potentially longevity in infants with GD.

Screening for patients with Gaucher's disease using routine pathology results: PATHFINDER (ferritin, alkaline phosphatase, platelets) study

AIMS

Lysosomal β-glucocerebrosidase A (GBA) deficiency causes Gaucher disease (GD), a recessive disorder caused by bi-allelic mutations in GBA. The prevalence of GD is associated with ethnicity but largely unknown and potentially underestimated in many countries. GD may manifest with organomegaly, bone involvement, and neurological symptoms as well as abnormal laboratory biomarkers. This study attempted to screen for GD in patients using abnormal platelet, alkaline phosphatase (ALP), and ferritin results from laboratory databases.

METHODS

Electronic laboratory databases were interrogated using a 2- to 4-year time interval to identify from clinical biochemistry records patients with a phenotype of reduced platelets (<150 × 10⁹ /L) and either elevated ALP (>130 iu/L) or ferritin [>150 (female) or >250 µg/L (male)]. The mean value over the screening window was used to reduce variability in results. A dried blood spot sample was collected for the determination of GBA activity in patients meeting these criteria. If low GBA activity was found, then the concentration of the GD-specific biomarker glucosyl-sphingosine (lyso-GB1) was assayed, and the GBA gene sequenced.

RESULTS

Samples were obtained from 1058 patients; 232 patients had low GBA activity triggering further analysis. No new cases of GD with homozygosity for pathogenic variants were identified, but 12 patients (1%) were identified to be carriers of a pathogenic variant in GBA.

CONCLUSIONS

Pathology databases hold routine information that can be used to screen for patients with inherited errors of metabolism. However, biochemical screening using mean platelets, ALP, and ferritin has a low yield for unidentified cases of GD.

Screening for Gaucher Disease Using Dried Blood Spot Tests: A Japanese Multicenter, Cross-sectional Survey

Objective For patients with Gaucher disease (GD), a rare, inherited lysosomal storage disease, obtaining a definitive diagnosis is currently time-consuming and costly. A simplified screening method to measure the glucocerebrosidase (GBA) activity using dried blood spots (DBS) on filter paper has recently been developed. Using this newly developed screening method, we evaluated real-world GD screening in patients suspected of having GD. Methods This multicenter, cross-sectional, observational study with a diagnostic intervention component evaluated real-world screening in patients suspected of having GD based on their clinical symptoms and a platelet count <120,000/μL. The endpoint was the number of patients with low GBA activity determined using DBS. Results In 994 patients who underwent initial DBS screening, 77 had low GBA activity. The assay was not repeated in 1 patient who was diagnosed as having a high possibility of GD due to clinical symptoms, and a further 21 patients completed the study without undergoing the second assay. Of the remaining 55 patients who had 2 DBS assays performed, 11 had a low GBA activity in both assays. Overall, DBS screening identified 12 (1.2%) patients with a low GBA activity, a proportion consistent with prior screening studies. Conclusion These results suggest that the simplified DBS method was less burdensome to patients, was easily utilized by many physicians, and could be a useful first-tier screening assay for GD prior to initiating burdensome genetic testing.

Pitfalls in the diagnosis of Gaucher disease in Iraq: A diagnostic experience from a developing country

Background and Objectives:

Gaucher disease (GD) is a rare hereditary disorder caused by deficiency of the lysosomal enzyme β-glucocerebrosidase. An early and definitive diagnosis minimizes the sequelae of misdiagnoses, and unnecessary and invasive diagnostic procedures.

Methods:

A cross-sectional descriptive study was conducted in the period from June to August, 2018, to analysing data of thirteen patients, retrospectively. They presented to the gastrointestinal and metabolic clinics in Children Welfare Teaching Hospital in Iraq, and had wrong and delayed diagnosis of GD.

Results:

Two groups of patients were identified, based on diagnosis by enzymatic assay (considering the test positive when the enzyme level is below the normal value); those who had false positive (low level of the enzyme) result and received enzyme replacement therapy for long time, and those who had false negative (normal level of the enzyme) results which caused delay in their diagnosis and treatment. Two main factors that misled the diagnosis were identified.

Conclusion:

Each patient with Gaucher disease need to be approached by taking a thorough history, a proper clinical examination, and then by being investigated, accordingly. Biomarkers and molecular genetic studies are more accurate and solid additional tools, to the enzymatic assays on dried blood sample (DBS).

High risk screening for Gaucher disease in patients with splenomegaly and/or thrombocytopenia in China: 55 cases identified

Gaucher disease (GD) is a common lysosomal storage disorder caused by deficiency of glucocerebrosidase (GCase) due to the pathogenic variants in the GBA gene. The aim of this study was to evaluate the performance of high risk screening program for GD by measuring the enzyme activities of GCase and chitotriosidease in dried blood spots of patients with splenomegaly and/or thrombocytopenia. A total of 787 subjects (364 females and 423 males) with unexplained splenomegaly and/or thrombocytopenia were enrolled in this study from May 2016 to Aug 2019. The cutoff value of GCase activity was set as less than 3.0 pmol/punch/h for screening positive. The diagnosis of GD was confirmed by Sanger sequencing of the GBA gene. Among 131 screening positive cases, 49 patients were confirmed GD. The positive predictive value was 37.4%.Three patients with boundary values (GCase 3-4 pmol/punch/h) and other three splenectomic patients with normal GCase activity were confirmed GD by GBA genetic analysis because of increased chitotriosidase or Gaucher cells in bone marrow. A total of 55 GD cases were identified. The sensitivity and specificity of the high risk screening were 98.2% and 89.5%, respectively. These 55 GD patients presented splenomegaly (100%), hepatomegaly (70.9%), thrombocytopenia (83.6%). The level of GCase in GD patients was (1.7 ± 1.6) pmol/punch/h. The increased chitotriosidase (383.8 ± 130.2 pmol/punch/h) was found in 42 (76.4%) patients with GD. Molecular genetic analysis identified 44 variants in the GBA gene, including 11 novel variants. The results showed the high risk screening for GD is accurate, rapid and cost-effective.

High-risk screening for Anderson-Fabry disease in patients with cardiac, renal, or neurological manifestations

Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder caused by abnormalities in the α-galactosidase (Gal) A gene (GLA; MIM:300644). The reduced activity of the lysosomal enzyme, α-galactosidase A (α-Gal A) leads to classic early manifestations and vascular disease of the heart, kidneys, and brain. As a high-risk screening for symptomatic AFD using an enzymatic assay on dried blood spot samples, we enrolled 2325 individuals (803 females and 1522 males; median age: 66 years) with cardiac, renal, or neurological manifestations that met at least one of the following criteria: (a) family history of early-onset cardiovascular diseases; (b) typical classic manifestations, such as acroparesthesias, clustered angiokeratoma, cornea verticillata, and hypo-anhidrosis; (c) proteinuria; (d) receiving dialysis; (e) left ventricular hypertrophy on electrocardiography or echocardiography; or (f) history of stroke. Ninety-two patients displayed low α-Gal A activity. Four males and two females had different pathogenic GLA mutations (0.26%) including a novel mutation c.908-928del21. Four males (0.17%) harbored the GLA c.196G>C (p.E66Q) variant. This simple screening protocol using dried blood spot samples is useful for early diagnosis of AFD in high-risk and underdiagnosed patients suffering from various cardiac, renal, or neurological manifestations.