scholarly journals At-Risk Testing for Pompe Disease Using Dried Blood Spots: Lessons Learned for Newborn Screening

2020 ◽  
Vol 6 (4) ◽  
pp. 96
Author(s):  
Zoltan Lukacs ◽  
Petra Oliva ◽  
Paulina Nieves Cobos ◽  
Jacob Scott ◽  
Thomas P. Mechtler ◽  
...  
Keyword(s):  
At Risk ◽  
Enzyme Activity ◽  
Newborn Screening ◽  
Pompe Disease ◽  
Age Of Onset ◽  
Late Onset ◽  
Dried Blood Spots ◽  
Lessons Learned ◽  
Unknown Etiology ◽  
Activity Measurement

Pompe disease (GSD II) is an autosomal recessive disorder caused by deficiency of the lysosomal enzyme acid-α-glucosidase (GAA, EC 3.2.1.20), leading to generalized accumulation of lysosomal glycogen especially in the heart, skeletal, and smooth muscle, and the nervous system. It is generally classified based on the age of onset as infantile (IOPD) presenting during the first year of life, and late onset (LOPD) when it presents afterwards. In our study, a cohort of 13,627 samples were tested between January 2017 and December 2018 for acid-α-glucosidase (GAA, EC 3.2.1.20) deficiency either by fluorometry or tandem mass spectrometry (MS). Testing was performed for patients who displayed conditions of unknown etiology, e.g., CK elevations or cardiomyopathy, in the case of infantile patients. On average 8% of samples showed activity below the reference range and were further assessed by another enzyme activity measurement or molecular genetic analysis. Pre-analytical conditions, like proper drying, greatly affect enzyme activity, and should be assessed with measurement of reference enzyme(s). In conclusion, at-risk testing can provide a good first step for the future introduction of newborn screening for Pompe disease. It yields immediate benefits for the patients regarding the availability and timeliness of the diagnosis. In addition, the laboratory can introduce the required methodology and gain insights in the evaluation of results in a lower throughput environment. Finally, awareness of such a rare condition is increased tremendously among local physicians which can aid in the introduction newborn screening.

scholarly journals Mass Spectrometry but Not Fluorimetry Distinguishes Affected and Pseudodeficiency Patients in Newborn Screening for Pompe Disease

2017 ◽  
Vol 63 (7) ◽  
pp. 1271-1277 ◽  
Author(s):  
Hsuan-Chieh Liao ◽  
Min-Ju Chan ◽  
Chia-Feng Yang ◽  
Chuan-Chi Chiang ◽  
Dau-Ming Niu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Newborn Screening ◽  
Pompe Disease ◽  
Late Onset ◽  
Asian Population ◽  
Dried Blood Spots ◽  
Fluorimetric Assay ◽  
Analytical Range ◽  
Patient Referrals

Abstract BACKGROUND Deficiency of the lysosomal enzyme acid α-glucosidase (GAA) causes Pompe disease. Newborn screening for Pompe disease is ongoing, and improved methods for distinguishing affected patients from those with pseudodeficiency, especially in the Asian population, would substantially reduce the number of patient referrals for clinical follow-up. METHODS We measured the enzymatic activity of GAA in dried blood spots on newborn screening cards (DBS) using a tandem mass spectrometry (MS/MS) assay. The assay displayed a relatively large analytical range compared to the fluorimetric assay with 4-methylumbelliferyl-α-glucoside. DBS from newborns confirmed to have infantile-onset Pompe disease (IOPD, n = 11) or late-onset Pompe disease (LOPD) (n = 12) and those from patients bearing pseudodeficiency alleles with or without Pompe mutations, or Pompe disease carriers (n = 230) were studied. RESULTS With use of the MS/MS GAA assay in DBS, 96% of the pseudodeficiency newborns and all of the Pompe disease carriers were well separated from the IOPD and LOPD newborns. The fluorimetric assay separated <10% of the pseudodeficiencies from the IOPD/LOPD group. CONCLUSIONS The relatively large analytical range MS/MS GAA assay but not the fluorimetric assay in DBS provides a robust approach to reduce the number of referrals and should dramatically facilitate newborn screening of Pompe disease.

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.

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.

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.

scholarly journals Clinical Analysis of Algerian Patients with Pompe Disease

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Y. Sifi ◽  
M. Medjroubi ◽  
R. Froissart ◽  
N. Taghane ◽  
K. Sifi ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Pompe Disease ◽  
Clinical Presentation ◽  
Age Of Onset ◽  
Late Onset ◽  
Disease Onset ◽  
Dried Blood Spots ◽  
Clinical Analysis ◽  
Pompe’S Disease ◽  
Pompe's Disease

Pompe’s disease is a metabolic myopathy caused by a deficiency of acid alpha-glucosidase (GAA), also called acid maltase, an enzyme that degrades lysosomal glycogen. The clinical presentation of Pompe’s disease is variable with respect to the age of onset and rate of disease progression. Patients with onset of symptoms in early infancy (infantile-onset Pompe disease (IOPD)) typically exhibit rapidly progressive hypertrophic cardiomyopathy and marked muscle weakness. Most of them die within the first year of life from cardiac and/or respiratory failure. In the majority of cases of Pompe’s disease, onset of symptoms occurs after infancy, ranging widely from the first to sixth decade of life (late-onset Pompe’s disease or LOPD). Progression of the disease is relentless and patients eventually progress to loss of ambulation and death due to respiratory failure. The objective of this study was to characterize the clinical presentation of 6 patients (3 with EOPD and the other 3 with LOPD) of 5 families from the East of Algeria. All our patients were diagnosed as having Pompe’s disease based on biochemical confirmations of GAA deficiency by dried blood spots (DBS) and GAA gene mutations were analyzed in all patients who consented (n=4). Our results are similar to other ethnic groups.

scholarly journals The First Year Experience of Newborn Screening for Pompe Disease in California

2020 ◽  
Vol 6 (1) ◽  
pp. 9 ◽  
Author(s):  
Hao Tang ◽  
Lisa Feuchtbaum ◽  
Stanley Sciortino ◽  
Jamie Matteson ◽  
Deepika Mathur ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Newborn Screening ◽  
Pompe Disease ◽  
Late Onset ◽  
First Year ◽  
Sequencing Analysis ◽  
Enzyme Activity Assay ◽  
California Department ◽  
Birth Prevalence ◽  
Gaa Gene

The California Department of Public Health started universal newborn screening for Pompe disease in August 2018 with a two-tier process including: (1) acid alpha-glucosidase (GAA) enzyme activity assay followed by, (2) GAA gene sequencing analysis. This study examines results from the first year of screening in a large and diverse screening population. With 453,152 screened newborns, the birth prevalence and GAA enzyme activity associated with various types of Pompe disease classifications are described. The frequency of GAA gene mutations and allele variants are reported. Of 88 screen positives, 18 newborns were resolved as Pompe disease, including 2 classic infantile-onset and 16 suspected late-onset form. The c.-32-13T>G variant was the most common pathogenic mutation reported. African American and Asian/Pacific Islander newborns had higher allele frequencies for both pathogenic and pseudodeficiency variants. After the first year of Pompe disease screening in California, the disease distribution in the population is now better understood. With the ongoing long-term follow-up system currently in place, our understanding of the complex genotype-phenotype relationships will become more evident in the future, and this should help us better understand the clinical significance of identified cases.

Determination of psychosine concentration in dried blood spots from newborns that were identified via newborn screening to be at risk for Krabbe disease

2013 ◽  
Vol 419 ◽  
pp. 73-76 ◽  
Author(s):  
Wei-Lien Chuang ◽  
Josh Pacheco ◽  
X. Kate Zhang ◽  
Monica M. Martin ◽  
Chad K. Biski ◽  
...  
Keyword(s):  
At Risk ◽  
Newborn Screening ◽  
Dried Blood Spots ◽  
Krabbe Disease ◽  
Blood Spots

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 Lessons Learned from Pompe Disease Newborn Screening and Follow-up

2020 ◽  
Vol 6 (1) ◽  
pp. 11
Author(s):  
Tracy L. Klug ◽  
Lori B. Swartz ◽  
Jon Washburn ◽  
Candice Brannen ◽  
Jami L. Kiesling
Keyword(s):  
Newborn Screening ◽  
Pompe Disease ◽  
Human Services ◽  
Lessons Learned ◽  
Lysosomal Storage ◽  
Health And Human Services ◽  
Disease Phenotypes ◽  
Department Of Health ◽  
The World

In 2015, Pompe disease became the first lysosomal storage disorder to be recommended for universal newborn screening by the Secretary of the U.S. Department of Health and Human Services. Newborn screening for Pompe has been implemented in 20 states and several countries across the world. The rates of later-onset disease phenotypes for Pompe and pseudodeficiency alleles are higher than initially anticipated, and these factors must be considered during Pompe disease newborn screening. This report presents an overview of six years of data from the Missouri State Public Health Laboratory for Pompe disease newborn screening and follow-up.

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