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 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.

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

Newborn screening for Pompe disease with dried blood spots in a Japanese region: a pilot study

2014 ◽  
Vol 111 (2) ◽  
pp. S79
Author(s):  
Ken Momosaki ◽  
Shirou Matsumoto ◽  
Kimitoshi Nakamura ◽  
Hiroshi Mitsubuchi ◽  
Toshika Okumiya ◽  
...  
Keyword(s):  
Pilot Study ◽  
Newborn Screening ◽  
Pompe Disease ◽  
Dried Blood Spots ◽  
Blood Spots

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.

Increased utility of dried blood spots in clinical diagnostic testing

2018 ◽  
Vol 123 (2) ◽  
pp. S120
Author(s):  
Laura Pollard ◽  
Rongrong Huang ◽  
Tim Wood
Keyword(s):  
Diagnostic Testing ◽  
Dried Blood Spots ◽  
Blood Spots ◽  
Clinical Diagnostic

scholarly journals Determination of Acid α-Glucosidase Protein: Evaluation as a Screening Marker for Pompe Disease and Other Lysosomal Storage Disorders

2000 ◽  
Vol 46 (9) ◽  
pp. 1318-1325 ◽  
Author(s):  
Kandiah Umapathysivam ◽  
Alison M Whittle ◽  
Enzo Ranieri ◽  
Colleen Bindloss ◽  
Elaine M Ravenscroft ◽  
...  
Keyword(s):  
Pompe Disease ◽  
Screening Program ◽  
Dried Blood Spots ◽  
Lysosomal Storage Disorders ◽  
Lysosomal Storage ◽  
Total Acid ◽  
Blood Spots ◽  
Enzyme Replacement ◽  
Storage Disorders

Abstract Background: In recent years, there have been significant advances in the development of enzyme replacement and other therapies for lysosomal storage disorders (LSDs). Early diagnosis, before the onset of irreversible pathology, has been demonstrated to be critical for maximum efficacy of current and proposed therapies. In the absence of a family history, the presymptomatic detection of these disorders ideally can be achieved through a newborn screening program. One approach to the development of such a program is the identification of suitable screening markers. In this study, the acid α-glucosidase protein was evaluated as a marker protein for Pompe disease and potentially for other LSDs. Methods: Two sensitive immunoquantification assays for the measurement of total (precursor and mature) and mature forms of acid α-glucosidase protein were used to determine the concentrations in plasma and dried blood spots from control and LSD-affected individuals. Results: In the majority of LSDs, no significant increases above control values were observed. However, individuals with Pompe disease showed a marked decrease in acid α-glucosidase protein in both plasma and whole blood compared with unaffected controls. For plasma samples, this assay gave a sensitivity of 95% with a specificity of 100%. For blood spot samples, the sensitivity was 82% with a specificity of 100%. Conclusions: This study demonstrates that it is possible to screen for Pompe disease by screening the concentration of total acid α-glucosidase in plasma or dried blood spots.

scholarly journals Newborn Screening for Pompe Disease: Pennsylvania Experience

2020 ◽  
Vol 6 (4) ◽  
pp. 89
Author(s):  
Can Ficicioglu ◽  
Rebecca C. Ahrens-Nicklas ◽  
Joshua Barch ◽  
Sanmati R. Cuddapah ◽  
Brenda S. DiBoscio ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Newborn Screening ◽  
Pompe Disease ◽  
Late Onset ◽  
Compound Heterozygous ◽  
Variant Of Unknown Significance ◽  
Unknown Significance ◽  
Second Tier ◽  
Alpha Glucosidase ◽  
Gaa Gene

Pennsylvania started newborn screening for Pompe disease in February 2016. Between February 2016 and December 2019, 531,139 newborns were screened. Alpha-Glucosidase (GAA) enzyme activity is measured by flow-injection tandem mass spectrometry (FIA/MS/MS) and full sequencing of the GAA gene is performed as a second-tier test in all newborns with low GAA enzyme activity [<2.10 micromole/L/h]. A total of 115 newborns had low GAA enzyme activity and abnormal genetic testing and were referred to metabolic centers. Two newborns were diagnosed with Infantile Onset Pompe Disease (IOPD), and 31 newborns were confirmed to have Late Onset Pompe Disease (LOPD). The incidence of IOPD + LOPD was 1:16,095. A total of 30 patients were compound heterozygous for one pathogenic and one variant of unknown significance (VUS) mutation or two VUS mutations and were defined as suspected LOPD. The incidence of IOPD + LOPD + suspected LOPD was 1: 8431 in PA. We also found 35 carriers, 15 pseudodeficiency carriers, and 2 false positive newborns.

GAA gene mutation detection following clinical evaluation and enzyme activity analysis in Azeri Turkish patients with Pompe disease

2020 ◽  
Vol 35 (7) ◽  
pp. 1127-1134
Author(s):  
Jalal Gharesouran ◽  
Abbas Jalaiei ◽  
Aida Hosseinzadeh ◽  
Soudeh Ghafouri-Fard ◽  
Zeinab Mokhtari ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Gene Mutation ◽  
Clinical Evaluation ◽  
Pompe Disease ◽  
Mutation Detection ◽  
Activity Analysis ◽  
Turkish Patients ◽  
Gaa Gene

scholarly journals Enzymatic diagnosis of Pompe disease: lessons from 28 years of experience

2020 ◽  
Author(s):  
Monica Y. Niño ◽  
Mark Wijgerde ◽  
Douglas Oliveira Soares de Faria ◽  
Marianne Hoogeveen-Westerveld ◽  
Atze J. Bergsma ◽  
...  
Keyword(s):  
Pompe Disease ◽  
Large Scale ◽  
Dried Blood Spots ◽  
Neuromuscular Disorder ◽  
Childhood Onset ◽  
Blood Spots ◽  
The Past ◽  
Biochemical Diagnosis ◽  
Clinical Diagnoses ◽  
Alpha Glucosidase

Abstract Pompe disease is a lysosomal and neuromuscular disorder caused by deficiency of acid alpha-glucosidase (GAA), and causes classic infantile, childhood onset, or adulthood onset phenotypes. The biochemical diagnosis is based on GAA activity assays in dried blood spots, leukocytes, or fibroblasts. Diagnosis can be complicated by the existence of pseudodeficiencies, i.e., GAA variants that lower GAA activity but do not cause Pompe disease. A large-scale comparison between these assays for patient samples, including exceptions and borderline cases, along with clinical diagnoses has not been reported so far. Here we analyzed GAA activity in a total of 1709 diagnostic cases over the past 28 years using a total of 2591 analyses and we confirmed the clinical diagnosis in 174 patients. We compared the following assays: leukocytes using glycogen or 4MUG as substrate, fibroblasts using 4MUG as substrate, and dried blood spots using 4MUG as substrate. In 794 individuals, two or more assays were performed. We found that phenotypes could only be distinguished using fibroblasts with 4MUG as substrate. Pseudodeficiencies caused by the GAA2 allele could be ruled out using 4MUG rather than glycogen as substrate in leukocytes or fibroblasts. The Asian pseudodeficiency could only be ruled out in fibroblasts using 4MUG as substrate. We conclude that fibroblasts using 4MUG as substrate provides the most reliable assay for biochemical diagnosis and can serve to validate results from leukocytes or dried blood spots.

scholarly journals Newborn Screening for Pompe Disease

2020 ◽  
Vol 6 (2) ◽  
pp. 31
Author(s):  
Takaaki Sawada ◽  
Jun Kido ◽  
Kimitoshi Nakamura
Keyword(s):  
Enzyme Activity ◽  
Newborn Screening ◽  
Pompe Disease ◽  
Autosomal Recessive Disorder ◽  
Glycogen Storage Disease Type ◽  
Dried Blood Spots ◽  
Glycogen Storage ◽  
Glycogen Accumulation ◽  
Enzyme Replacement ◽  
Asian Populations

Glycogen storage disease type II (also known as Pompe disease (PD)) is an autosomal recessive disorder caused by defects in α-glucosidase (AαGlu), resulting in lysosomal glycogen accumulation in skeletal and heart muscles. Accumulation and tissue damage rates depend on residual enzyme activity. Enzyme replacement therapy (ERT) should be started before symptoms are apparent in order to achieve optimal outcomes. Early initiation of ERT in infantile-onset PD improves survival, reduces the need for ventilation, results in earlier independent walking, and enhances patient quality of life. Newborn screening (NBS) is the optimal approach for early diagnosis and treatment of PD. In NBS for PD, measurement of AαGlu enzyme activity in dried blood spots (DBSs) is conducted using fluorometry, tandem mass spectrometry, or digital microfluidic fluorometry. The presence of pseudodeficiency alleles, which are frequent in Asian populations, interferes with NBS for PD, and current NBS systems cannot discriminate between pseudodeficiency and cases with PD or potential PD. The combination of GAA gene analysis with NBS is essential for definitive diagnoses of PD. In this review, we introduce our experiences and discuss NBS programs for PD implemented in various countries.

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