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

High-risk screening for late-onset Pompe disease in China: An expanded multicenter study

Late-onset Pompe disease (LOPD) is caused by a genetic deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA), leading to progressive limb-girdle weakness and respiratory impairment. The insidious onset of non-specific early symptoms often prohibits timely diagnosis. This study aimed to validate the high-risk screening criteria for LOPD in the Chinese population. A total of 726 patients were included, including 96 patients under 14 years of age. Dried blood spots (DBS) and tandem mass spectrometry (MS/MS) were employed to evaluate serum GAA activity. Forty-four patients exhibited a decreased GAA activity, 16 (2.2%) of which were confirmed as LOPD by genetic testing. Three previously unreported GAA mutations were also identified. The median diagnostic delay was shortened to 3 years, which excelled the previous retrospective studies. At diagnosis, most patients exhibited impaired respiratory function and/or limb-girdle weakness. Elevated serum creatine kinase (CK) levels were more frequently observed in patients who manifested before age 16. Overall, high-risk screening is a feasible and efficient method to identify LOPD patients at an early stage. Patients over 1 year of age with either weakness in axial and/or proximal limb muscles, or unexplained respiratory distress shall be subject to GAA enzymatic test, while CK levels above 2 times the upper normal limit shall be an additional criterion for patients under 16. This modified high-risk screening criteria for LOPD requires further validation in larger Chinese cohorts.

Gaucher Disease or Acid Sphingomyelinase Deficiency? The Importance of Differential Diagnosis

Background: Gaucher disease is a lysosomal storage disorder caused by functional glucocerebrosidase enzyme deficiency. Hepatosplenomegaly and hematological complications are found in both Gaucher disease and Acid Sphingomyelinase Deficiency, which is caused by acid sphingomyelinase dysfunction. The possible overlap in clinical presentation can cause diagnostic errors in differential diagnosis. For this reason, in patients with an initial clinical suspicion of Gaucher disease, we aimed to carry out a parallel screening of acid sphingomyelinase and glucocerebrosidase. Methods: Peripheral blood samples of 627 patients were collected, and enzymatic activity analysis was performed on both glucocerebrosidase and acid sphingomyelinase. The specific gene was studied in samples with null or reduced enzymatic activity. Specific molecular biomarkers helped to achieve the correct diagnosis. Results: In 98.7% of patients, normal values of glucocerebrosidase activity excluded Gaucher disease. In 8 of 627 patients (1.3%), the glucocerebrosidase enzymatic activity assay was below the normal range, so genetic GBA1 analysis confirmed the enzymatic defect. Three patients (0.5%) had normal glucocerebrosidase activity, so they were not affected by Gaucher disease, and showed decreased acid sphingomyelinase activity. SMPD1 gene mutations responsible for Acid Sphingomyelinase Deficiency were found. The levels of specific biomarkers found in these patients further strengthened the genetic data. Conclusions: Our results suggest that in the presence of typical signs and symptoms of Gaucher disease, Acid Sphingomyelinase Deficiency should be considered. For this reason, the presence of hepatosplenomegaly, thrombocytopenia, leukocytopenia, and anemia should alert clinicians to analyze both enzymes by a combined screening. Today, enzyme replacement therapy is available for the treatment of both pathologies; therefore, prompt diagnosis is essential for patients to start accurate treatment and to avoid diagnostic delay.

[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.

Similarities and differences between Gaucher disease and acid sphingomyelinase deficiency: An algorithm to support the diagnosis

Lysosomal storage disorders are a group of inborn errors of metabolism due to defects in proteins crucial for lysosomal function. Gaucher disease is the most common autosomal recessive lysosomal storage disorder due to mutations in the GBA1 gene, resulting in the lysosomal deficiency of glucocerebrosidase activity. Gaucher disease is characterized by the toxic accumulation of glucosylceramide in the reticuloendothelial system. Acid sphingomyelinase deficiency (ASMD), previously known as Niemann Pick A/B disease, is also an autosomal recessive lysosomal storage disorder due to mutations in the SMPD1 gene, which result in acid sphingomyelinase deficiency and the accumulation of sphingomyelin in mononuclear phagocytic system and hepatocytes. The phenotypic expression of Gaucher disease type 1 (GD1), the most common type, and chronic visceral ASMD may overlap for several signs or symptoms. Splenomegaly is detectable in approximately 90% of the patients in both conditions; however, since GD1 is more frequent than ASMD, clinicians are more prone to suspect it, often neglecting the diagnosis of ASMD. Based on previous experience, a group of experts in the clinical and laboratory diagnosis, management, and treatment of lysosomal storage disorders developed an algorithm for both GD1 and ASMD to support physicians, including primary care providers, internists, and specialists (e.g., hepatologists, hematologists, and pulmonologists) to suspect and differentiate GD1 and ASMD and to provide the appropriate referral.

The molecular mechanism of Gaucher disease caused by compound heterozygous mutations in GBA1 gene

Gaucher disease (GD, ORPHA355) is a rare autosomal recessive genetic disease caused by mutations in GBA1, which encodes the lysosomal enzyme glucocerebrosidase (GCase). Here, we report a patient with GD who carried the heterozygous c.1240G > C (p.Val414Leu) mutation and the heterozygous pathogenic c.1342G > C (p.Asp448His) mutation in GBA1. Bioinformatics analysis suggested that the two mutations are pathogenic. Functional studies showed that GBA1 mRNA and GCase protein levels of mutant types were significantly less than the wild-type. In the cell lysates, the two mutations of GBA1 c.1240G > C and c.1342G > C caused a decreased GCase concentration, while the two mutations did not change the distribution in the cell. The pathogenicity of the compound heterozygous mutations was verified. Early diagnosis and treatment can improve the quality of life and prevent unnecessary procedures in patients with GD.

Patient centered guidelines for the laboratory diagnosis of Gaucher disease type 1

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder due to the deficient activity of the acid beta-glucosidase (GCase) enzyme, resulting in the progressive lysosomal accumulation of glucosylceramide (GlcCer) and its deacylated derivate, glucosylsphingosine (GlcSph). GCase is encoded by the GBA1 gene, located on chromosome 1q21 16 kb upstream from a highly homologous pseudogene. To date, more than 400 GBA1 pathogenic variants have been reported, many of them derived from recombination events between the gene and the pseudogene. In the last years, the increased access to new technologies has led to an exponential growth in the number of diagnostic laboratories offering GD testing. However, both biochemical and genetic diagnosis of GD are challenging and to date no specific evidence-based guidelines for the laboratory diagnosis of GD have been published. The objective of the guidelines presented here is to provide evidence-based recommendations for the technical implementation and interpretation of biochemical and genetic testing for the diagnosis of GD to ensure a timely and accurate diagnosis for patients with GD worldwide. The guidelines have been developed by members of the Diagnostic Working group of the International Working Group of Gaucher Disease (IWGGD), a non-profit network established to promote clinical and basic research into GD for the ultimate purpose of improving the lives of patients with this disease. One of the goals of the IWGGD is to support equitable access to diagnosis of GD and to standardize procedures to ensure an accurate diagnosis. Therefore, a guideline development group consisting of biochemists and geneticists working in the field of GD diagnosis was established and a list of topics to be discussed was selected. In these guidelines, twenty recommendations are provided based on information gathered through a systematic review of the literature and two different diagnostic algorithms are presented, considering the geographical differences in the access to diagnostic services. Besides, several gaps in the current diagnostic workflow were identified and actions to fulfill them were taken within the IWGGD. We believe that the implementation of recommendations provided in these guidelines will promote an equitable, timely and accurate diagnosis for patients with GD worldwide.

Targeted Screening for Gaucher Disease in High Suspicion Patients and Clinical Profile of Screen Positives in a Large Pediatric Multispecialty Hospital

OBJECTIVES

 The proposed screening study was aimed at determining the prevalence of Gaucher disease in a selected high-risk population of patients and describing the clinical profile of diagnosed patients.

METHODOLOGY

It was a prospective observational study from January 2020 to September 2022 (two years and eight months) in the genetic clinic of the pediatric department. A total of 22 patients were suspected to be having Gaucher disease based on clinical findings of hepatosplenomegaly with bicytopenia or isolated thrombocytopenia. In these patients, chronic liver disease, portal hypertension, and other hematological conditions were ruled out. Three patients with Gaucher disease applied for enzyme replacement therapy (ERT) support under India Charitable Access Program and one patient received therapy for two months. Clinical findings were compared before and after ERT. Clinical findings were noted in all patients.

RESULTS

 Among the 22 patients, nine (40.9%) patients were confirmed to be suffering from Gaucher disease with six based on enzyme assay on dry blood spot and three based on DNA mutation analysis. One patient among the screen positives received ERT for two months and was noted to have an improvement in hemoglobin and platelet count, a reduction in liver size, and better general well-being.

CONCLUSION

High-suspicion targeted screening of Gaucher disease in patients with splenomegaly and thrombocytopenia based on a dry blood spot enzyme assay is high yielding, effective strategy in identifying Gaucher disease patients. Clinical features were variable in severity, though a common mutation was found in the majority of patients.

Bone disease in early detected Gaucher Type I disease: A case report

Gaucher disease (GD) is a lysosomal disorder characterized by the storage of glucosylceramide in macrophages ("Gaucher cells"), particularly in the spleen, liver, and bone marrow. The most common phenotype, GD type 1, usually presents with hepatosplenomegaly, cytopenias, and sometimes bone involvement at variable age. Enzyme replacement therapy (ERT) is available and effective, but some severe manifestations are irreversible (e.g., osteonecrosis), so that early treatment is crucial. We describe a 4-year-old Albanian male with GD type 1, diagnosed through newborn screening (NBS), presented during follow up with multiple osteonecrotic areas in both femurs. He had no other symptoms or signs of disease, except for increasing of lyso-Gb1 biomarker. Early initiation of ERT allowed a partial improvement of bone lesions. Our case highlights the importance of NBS for GD and of close follow-up of presymptomatic patients, especially if biomarker levels are increasing. In the absence of NBS, GD should be considered in patients who present with bone lesions, also isolated. Early diagnosis and treatment improve the course of disease and avoid irreversible sequelae.

The diagnosis and management of Gaucher disease in pediatric patients: Where do we go from here?

Gaucher disease (GD) is an autosomal recessive inherited lysosomal storage disease that often presents in early childhood and is associated with damage to multiple organ systems. Many challenges associated with GD diagnosis and management arise from the considerable heterogeneity of disease presentations and natural history. Phenotypic classification has traditionally been based on the absence (in type 1 GD) or presence (in types 2 and 3 GD) of neurological involvement of varying severity. However, patient management and prediction of prognosis may be best served by a dynamic, evolving definition of individual phenotype rather than by a rigid system of classification. Patients may experience considerable delays in diagnosis, which can potentially be reduced by effective screening programs; however, program implementation can involve ethical and practical challenges. Variation in the clinical course of GD and an uncertain prognosis also complicate decisions concerning treatment initiation, with differing stakeholder perspectives around efficacy and acceptable cost/benefit ratio. We review the challenges faced by physicians in the diagnosis and management of GD in pediatric patients. We also consider future directions and goals, including acceleration of accurate diagnosis, improvements in the understanding of disease heterogeneity (natural history, response to treatment, and prognosis), the need for new treatments to address unmet needs for all forms of GD, and refinement of the tools for monitoring disease progression and treatment efficacy, such as specific biomarkers.

Screening, patient identification, evaluation, and treatment in patients with Gaucher disease: Results from a Delphi consensus

Several guidelines are available for identification and management of patients with Gaucher disease, but the most recent guideline was published in 2013. Since then, there have been significant advances in newborn screening, phenotypic characterization, identification of biomarkers and their integration into clinical practice, and the development and approval of new treatment options. Accordingly, the goal of this Delphi consensus exercise was to extend prior initiatives of this type by addressing issues related to newborn screening, diagnostic evaluations, and treatment (both disease directed and adjunctive). The iterative Delphi process involved creation of an initial slate of statements, review by a steering committee, and three rounds of consensus development by an independent panel. A preliminary set of statements was developed by the supporting agency based on literature searches covering the period from 1965 to 2020. The Delphi process reduced an initial set of 185 statements to 65 for which there was unanimous support from the panel. The statements supported may ultimately provide a framework for more detailed treatment guidelines. In addition, the statements for which unanimous support could not be achieved help to identify evidence gaps that are targets for future research.

Novel Management and Screening Approaches for Haematological Complications of Gaucher's Disease

Purpose

Gaucher disease (GD) is the most common lysosomal storage disorder. The principal manifestations for its diagnosis and further monitoring include haematological manifestations such as anaemia, thrombocytopaenia, spleen enlargement, and bleeding disorders, among others. This review aims to summarise and update the role of haematological complications in GD diagnosis and follow-up, describe their management strategies, and to use these indicators as part of the diagnostic approach.

Materials and Methods

A systematic review following the recommendations of PRISMA-P 2020 was carried out. Publications indexed in the databases PubMed, Embase, Science Open, Mendeley, and Web of Science were electronically searched by three independent reviewers, and publications up to June 2021 were accessed. A total of 246 publications were initially listed, of which 129 were included for further review and analysis. Case reports were considered if they were representative of a relevant hematologic complication.

Results

From the first review dated in 1974 to the latest publication in 2021, including different populations confirmed that the haematological manifestations such as thrombocytopaenia and splenomegaly at diagnosis of GD type 1 are the most frequent features of the disease. The incorporation of haematological parameters to diagnosis strategies increases their cost-effectiveness. Hematologic parameters are part of the scoring system for disease assessment and the evaluation of therapeutic outcomes, providing reliable and accessible data to improve the management of GD. However, cytopaenia, underlying coagulation disorders, and platelet dysfunction need to be addressed, especially during pregnancy or surgery. Long-term haematological complications include the risk of neoplasia and immune impairment, an area of unmet need that is currently under research.

Conclusion

Haematological features are key for GD suspicion, diagnosis, and management. Normalization of hematological parameters is achieved with the treatment; however, there are unmet needs such as the underlying inflammatory status and the long-term risk of hematologic neoplasia.

Long-term safety and effectiveness of velaglucerase alfa in Gaucher disease: 6-year interim analysis of a post-marketing surveillance in Japan

BACKGROUND

Gaucher disease (GD) is caused by reduced lysosomal enzyme β-glucocerebrosidase activity. Heterogeneous genotypes and phenotypes have been observed within GD types and across ethnicities. Enzyme replacement therapy is generally recommended for patients with type 1 GD, the least severe form of GD. In Japan, velaglucerase alfa has a broad indication covering type 1, 2 or 3 GD.  METHODS: All patients with type 1, 2, or 3 GD administered velaglucerase alfa 60 U/kg every 2 weeks via intravenous infusion after its launch date in Japan in 2014, were enrolled in a non-interventional, observational post-marketing surveillance (PMS). Individual patient data were reported via case report forms (CRFs). Key safety endpoints investigated included the incidence of infusion-related reactions (IRRs), the safety of velaglucerase alfa in patients with types 2 and 3 GD, from patients under one year of age to elderly patients (≥ 65 years of age). Long-term efficacy was also assessed.  RESULTS: In total, 53 patients with GD were registered. CRFs were available for 41 (77.4%) patients at the 6-year interim analysis. Fourteen adverse drug reactions (ADRs) were reported in seven patients. All reported ADRs occurred in patients with type 2 GD. ADRs were reported by 63.6% (7/11) of patients with type 2 GD. Ten ADRs were reported in five patients aged < 4 years. No elderly patients experienced any ADR during the surveillance period. Five ADRs occurring in three (10.0%) patients were classified as IRRs, with one case of vomiting (moderate severity) resulting in treatment discontinuation. Ten serious adverse events were reported in five (16.7%) patients. Three fatal events were considered to be unrelated to treatment with velaglucerase alfa. Platelet counts increased after the administration of velaglucerase alfa and were generally maintained within the normal range over the administration period. Among eleven patients tested for neutralizing anti-velaglucerase alfa antibodies, two (18.2%) were assessed as positive results.  CONCLUSION: PMS data from patients with types 1-3 GD in Japan indicate that long-term treatment with velaglucerase alfa was well-tolerated and associated with increased platelet counts, which is consistent with observations made in studies outside of Japan.

TRIAL REGISTRATION

NCT03625882 registered July 2014.

Economic burden and health related quality of life of ultra-rare Gaucher disease in China

Background

The diagnosis and health care of patients with rare diseases present a tremendous challenge worldwide. This study described the health care service utilization through participants’ perspective and estimated the cost of illness (COI), and patients with Gaucher disease (GD)’s/caregivers’ health-related quality of life in China.

Method

An online retrospective survey of patients with GD and their caregivers was conducted during May–June 2018. Socio-demographic, health service utilization, disease-related expenses, social support, sleep quality (Pittsburgh Sleep Quality Index [PSQI]), and the Short Form Health Survey (SF-36) were investigated. Using self-reported information, we estimated the annual COI, including direct healthcare, direct non-healthcare, and indirect costs.

Results

Forty patients and their 49 caregivers were surveyed. The patients’ onset age of GD was 9.3 ± 10.9; their disease course was 3.5 ± 3.1 years. 21 (42.9%) patients had ≥ 2 caregivers, but 35 (71.4%) caregivers reported have no experience as a caregiver. 79.6% caregivers have stopped working, and 87.8% changed weekly working schedule. Before final diagnosis, patients visited 3.9 ± 3.1 (max = 20) hospitals and took 1.2 ± 1.7 (max = 6.6) years for confirmed diagnosis. On average, 5.0 ± 9.6 misdiagnoses occurred, and the per-patient diagnoses cost was USD ($) 7576. After GD confirmation, 8 (16.3%) patients received no treatment, 40 (81.6%) received pharmacotherapy, 10 (20.4%) received surgery, 38 (77.6%) received outpatient service (8.8 ± 9.1 times/annually), and 37 (77.5%) received inpatient service (4.0 ± 3.5 times/annually). Annual per-patient COI was USD ($) 49,925 (95% confidence interval: 29,178, 70,672). Average direct healthcare cost was $41,816, including pharmaceutical ($29,908), inpatient ($7,451), and outpatient ($1,838). Productivity loss per-caregiver was $1,980, and their Zarit Burden Inventory score was moderate-severe (48.6 ± 19.6). Both patients/caregivers reported lower social support (32.4 ± 7.4, 34.9 ± 7.6), two times higher PSQI (7.9 ± 2.9, 8.7 ± 3.6), and half lower SF-36 (41.3 ± 18.6, 46.5 ± 19.3) than those reported for healthy Chinese individuals.

Conclusions

The high misdiagnosis rate, together with delayed diagnosis, substantial costs, and deteriorated health-related quality of life of GD patients as well as their heavy care burden, calls for extreme attention from policymakers in China. Further efforts of government and society are urgently demanded, including pharmaceutical reimbursement, screening newborns, developing precise diagnostic tools, and training doctors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01963-6.

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.

Predicting the probability of Gaucher disease in subjects with splenomegaly and thrombocytopenia

Hematologists are frequently involved in the diagnostic pathway of Gaucher disease type 1 (GD1) patients since they present several hematological signs. However, GD1 is mainly underdiagnosed because of a lack of awareness. In this multicenter study, we combine the use of a diagnostic algorithm with a simple test (β-glucosidase activity on Dried Blood Spot) in order to facilitate the diagnosis in a population presenting to the hematologist with splenomegaly and/or thrombocytopenia associated with other hematological signs. In this high-risk population, the prevalence of GD1 is 3.3%. We propose an equation that predicts the probability of having GD1 according to three parameters that are routinely evaluated: platelet count, ferritin, and transferrin saturation.

Detection of glucosylsphingosine in dried blood spots for diagnosis of Gaucher disease by LC-MS/MS

INTRODUCTION

Gaucher disease (GD) is caused by a deficiency of β-glucosidase (GCase), leading to accumulation of glucosylceramide (GlcC) and glucosylsphingosine (Lyso-Gb1). Lyso-Gb1 is a reliable biomarker for GD.

OBJECTIVES

This study aims to develop a simple, effective and accurate method for the screening and diagnosis of GD using dried blood spot (DBS) samples.

METHODS

Lyso-Gb1 in DBS was extracted by 50% acetonitrile aqueous solution containing isotope-labeled internal standard and analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS). A reference interval was established by analyzing samples from 277 healthy controls. Lyso-Gb1 was detected in the residual DBS samples from 142 high-risk patients with splenomegaly and/or thrombocytopenia. Based on GCase activity in DBS, samples were classified into four groups: confirmed GD patients (n = 52), GD carriers (n = 5), false positive (n = 36) and negative (n = 49).

RESULTS

The optimized Lyso-Gb1 assay showed intra- and inter-assay variations ranged between 2.0%-8.2% and 3.8%-10.2%, respectively. Accuracies ranged from 93.5% to 112.6%. The lowest limit of quantification was 1 ng/mL. The normal reference interval of Lyso-Gb1 in DBS ranged from 2.1 to 9.9 ng/mL. Among the 142 subjects, except for one GD patient (Lyso-Gb1 > 2500 ng/mL), the Lyso-Gb1 concentrations in 51 GD patients ranged from 190.5 to 2380.6 ng/mL (the median 614.8 ng/mL). Also, one negative patient was found to have an elevated Lyso-Gb1 level (684.5 ng/mL), while the other patients were normal. The negative case was then confirmed to be an atypical GD patient with a c.1091A > G (p.Y364C) homozygous variant in PSAP gene by next generation sequencing.

CONCLUSIONS

The optimized method to determine Lyso-Gb1 in DBS was demonstrated as a useful tool for the screening and diagnosis of GD.