Accuracy diagnosis improvement of Fabry disease from dried blood spots: Enzyme activity, lyso‐Gb3 accumulation and GLA gene sequencing

2021 ◽  
Author(s):  
Rocío Delarosa‐Rodríguez ◽  
José D. Santotoribio ◽  
Hernández‐Arévalo Paula ◽  
Antonio González‐Meneses ◽  
Salvador García‐Morillo ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Fabry Disease ◽  
Gene Sequencing ◽  
Dried Blood Spots ◽  
Blood Spots ◽  
Gla Gene

Blood-based diagnostic testing for Pompe disease: Consistency between GAA enzyme activity in dried blood spots and GAA gene sequencing results

2014 ◽  
Vol 49 (5) ◽  
pp. 775-776 ◽  
Author(s):  
Jennifer L. Goldstein ◽  
Gwen Dickerson ◽  
Priya S. Kishnani ◽  
Catherine Rehder ◽  
Deeksha S. Bali
Keyword(s):  
Enzyme Activity ◽  
Pompe Disease ◽  
Diagnostic Testing ◽  
Gene Sequencing ◽  
Dried Blood Spots ◽  
Blood Spots ◽  
Gaa Gene

scholarly journals Spectrophotometric Microassay for δ-Aminolevulinate Dehydratase in Dried-Blood Spots as Confirmation for Hereditary Tyrosinemia Type I

2001 ◽  
Vol 47 (8) ◽  
pp. 1424-1429 ◽  
Author(s):  
Andreas Schulze ◽  
David Frommhold ◽  
Georg F Hoffmann ◽  
Ertan Mayatepek
Keyword(s):  
Enzyme Activity ◽  
Neonatal Screening ◽  
Dried Blood Spots ◽  
Confirmatory Test ◽  
Type I ◽  
Screening Programs ◽  
Blood Spots ◽  
Tyrosinemia Type I ◽  
Aminolevulinate Dehydratase ◽  
Hereditary Tyrosinemia

Abstract Background: Hereditary tyrosinemia type I (HT) fulfills the criteria for inclusion in neonatal screening programs, but measurement of tyrosine lacks clinical specificity and quantitative assay of succinylacetone is laborious. We developed a semiquantitative assay based on inhibition of δ-aminolevulinate dehydratase (ALA-D) by succinylacetone. Methods: Preincubation of 3-mm discs from dried-blood spots and reaction of the enzyme with δ-aminolevulinic acid as substrate were performed in microtiter plates. After separation of the supernatant and 10 min of color reaction with modified Ehrlich reagent, the formation of porphobilinogen was measured at 550 nm in a plate reader. Results: The detection limit for succinylacetone was 0.3 μmol/L; imprecision (CV) was <5.5% within-run and 10–16% between-run. Storage of blood spots at ambient temperature for several days led to a significant decrease of ALA-D activity. Enzyme activity was lost in filter cards at 45 °C, but remained stable at 2–37 °C. Enzyme activity was decreased in EDTA blood. The absorbance at 550 nm was 0.221 (± 0.073) in healthy neonates and 0.043–0.100 in 11 patients with HT. All neonates with increased tyrosine (above the 99.5th centile) in neonatal screening (97 of 47 000) had normal results by the new assay. Conclusions: The spectrophotometric microassay for ALA-D is a simple and sensitive test for HT. This represents a basis for further examination of its general reliability as a confirmatory test if tyrosine is found to be increased.

scholarly journals Assessment of Gene Variant Amenability for Pharmacological Chaperone Therapy with 1-Deoxygalactonojirimycin in Fabry Disease

2020 ◽  
Vol 21 (3) ◽  
pp. 956 ◽  
Author(s):  
Jan Lukas ◽  
Chiara Cimmaruta ◽  
Ludovica Liguori ◽  
Supansa Pantoom ◽  
Katharina Iwanov ◽  
...  
Keyword(s):  
Cell Culture ◽  
Enzyme Activity ◽  
Fabry Disease ◽  
Response Threshold ◽  
Clinical Indication ◽  
Gene Variants ◽  
Absolute Increase ◽  
Pharmacological Chaperone ◽  
Gla Gene ◽  
The Impact

Fabry disease is one of the most common lysosomal storage disorders caused by mutations in the gene encoding lysosomal α-galactosidase A (α-Gal A) and resultant accumulation of glycosphingolipids. The sugar mimetic 1-deoxygalactonojirimycin (DGJ), an orally available pharmacological chaperone, was clinically approved as an alternative to intravenous enzyme replacement therapy. The decision as to whether a patient should be treated with DGJ depends on the genetic variant within the α-galactosidase A encoding gene (GLA). A good laboratory practice (GLP)-validated cell culture-based assay to investigate the biochemical responsiveness of the variants is currently the only source available to obtain pivotal information about susceptibility to treatment. Herein, variants were defined amenable when an absolute increase in enzyme activity of ≥3% of wild type enzyme activity and a relative increase in enzyme activity of ≥1.2-fold was achieved following DGJ treatment. Efficacy testing was carried out for over 1000 identified GLA variants in cell culture. Recent data suggest that about one-third of the variants comply with the amenability criteria. A recent study highlighted the impact of inter-assay variability on DGJ amenability, thereby reducing the power of the assay to predict eligible patients. This prompted us to compare our own α-galactosidase A enzyme activity data in a very similar in-house developed assay with those from the GLP assay. In an essentially retrospective approach, we reviewed 148 GLA gene variants from our former studies for which enzyme data from the GLP study were available and added novel data for 30 variants. We also present data for 18 GLA gene variants for which no data from the GLP assay are currently available. We found that both differences in experimental biochemical data and the criteria for the classification of amenability cause inter-assay discrepancy. We conclude that low baseline activity, borderline biochemical responsiveness, and inter-assay discrepancy are alarm signals for misclassifying a variant that must not be ignored. Furthermore, there is no solid basis for setting a minimum response threshold on which a clinical indication with DGJ can be justified.

scholarly journals Fabry disease screening in high-risk populations in Japan: A nationwide study

2020 ◽  
Author(s):  
Shinichiro Yoshida ◽  
Jun Kido ◽  
Takaaki Sawada ◽  
Ken Momosaki ◽  
Keishin Sugawara ◽  
...  
Keyword(s):  
High Risk ◽  
Fabry Disease ◽  
Dried Blood Spots ◽  
Neurological Manifestations ◽  
Study Results ◽  
Novel Variants ◽  
Screening Study ◽  
Screening Protocol ◽  
High Risk Populations ◽  
Gla Gene

Abstract Background: Fabry disease (FD) is a X-linked inherited disorder caused by mutations in the GLA gene, which results in the deficiency of α-galactosidase A (α-Gal A). This leads to the progressive accumulation of metabolites, which can cause multisystemic dysfunction. A recent screening study among neonates reported an increase in the incidence of FD, and numerous FD patients remain undiagnosed or even misdiagnosed . Therefore, this study aimed to identify patients with FD by performing high-risk screening in 18,135 individuals, enrolled from October 2006 to March 2019, with renal, cardiac, or neurological manifestations from all prefectures in Japan . A total of 601 hospitals participated in this study. Results: Low α-Gal A activity was detected in 846 individuals, with 224 of them diagnosed with FD by GLA sequencing. Cases with a family history of FD (n = 64) were also subjected to sequencing, without α-Gal A assay, as per individual request, and 12 of them were diagnosed with a variant of FD. A total of 236 patients with FD (97 males and 139 females) were identified from among 18,199 participants. A total of 101 GLA variants, including 26 novel variants, were detected in the 236 patients with FD from 143 families, with 39 amenable variants (39%) and 79 of the 236 patients (33%) suitable for migalastat treatment. Conclusions: From among 18,199 participants, 101 GLA variants, including 26 novel variants, were identified in the 236 patients with FD from 143 families. Migalastat was identified as a suitable treatment option in 33% of the patients with FD and 39% of the GLA variants were detected as amenable. Therefore, the simple screening protocol using dried blood spots that was performed in this study could be useful for early diagnosis and selection of appropriate treatments for FD in high-risk and underdiagnosed patients with various renal, cardiac, or neurological manifestations.

scholarly journals Late-onset Pompe disease: what is the prevalence of limb-girdle muscular weakness presentation?

2018 ◽  
Vol 76 (4) ◽  
pp. 247-251 ◽  
Author(s):  
Paulo José Lorenzoni ◽  
Cláudia Suemi Kamoi Kay ◽  
Nádia Sugano Higashi ◽  
Vânia D'Almeida ◽  
Lineu Cesar Werneck ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Muscle Biopsy ◽  
Pompe Disease ◽  
Late Onset ◽  
Dried Blood Spots ◽  
Muscular Weakness ◽  
Inherited Disease ◽  
Blood Spots ◽  
Vacuolar Myopathy ◽  
Gaa Gene

ABSTRACT Pompe disease is an inherited disease caused by acid alpha-glucosidase (GAA) deficiency. A single center observational study aimed at assessing the prevalence of late-onset Pompe disease in a high-risk Brazilian population, using the dried blood spot test to detect GAA deficiency as a main screening tool. Dried blood spots were collected for GAA activity assay from 24 patients with “unexplained” limb-girdle muscular weakness without vacuolar myopathy in their muscle biopsy. Samples with reduced enzyme activity were also investigated for GAA gene mutations. Of the 24 patients with dried blood spots, one patient (4.2%) showed low GAA enzyme activity (NaG/AaGIA: 40.42; %INH: 87.22%). In this patient, genetic analysis confirmed two heterozygous mutations in the GAA gene (c.-32-13T>G/p.Arg854Ter). Our data confirm that clinicians should look for late-onset Pompe disease in patients whose clinical manifestation is an “unexplained” limb-girdle weakness even without vacuolar myopathy in muscle biopsy.

Effect of sample collection on α-galactosidase A enzyme activity measurements in dried blood spots on filter paper

2009 ◽  
Vol 403 (1-2) ◽  
pp. 159-162 ◽  
Author(s):  
Petra Olivova ◽  
Kristen van der Veen ◽  
Emmaline Cullen ◽  
Michael Rose ◽  
X. Kate Zhang ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Filter Paper ◽  
Dried Blood Spots ◽  
Sample Collection ◽  
Blood Spots ◽  
Activity Measurements

scholarly journals Correlation of Lyso-Gb3 levels in dried blood spots and sera from patients with classic and Later-Onset Fabry disease

2017 ◽  
Vol 121 (4) ◽  
pp. 320-324 ◽  
Author(s):  
Albina Nowak ◽  
Thomas Mechtler ◽  
David C. Kasper ◽  
Robert J. Desnick
Keyword(s):  
Fabry Disease ◽  
Dried Blood Spots ◽  
Blood Spots
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