Prevalence Of Late-onset Pompe Disease Research Articles

Global birth prevalence of Pompe disease: A systematic review and meta-analysis

BackgroundPompe disease, also known as Glycogen storage disease type II, is an autosomal recessive disorder caused by defects in alpha-glucosidase, resulting in abnormal glycogen accumulation. MethodsTo conduct a systematic review and meta-analysis of birth prevalence of Pompe disease, the MEDLINE and EMBASE databases were searched for original research articles on the epidemiology of Pompe disease from inception until July 01, 2024. Meta-analysis was performed to estimate global birth prevalence of Pompe disease. The funnel plot was used to describe potential publication bias. ResultsTwenty-two studies, screened out of 945 records, were included for data extraction. Studies that fulfilled inclusion criteria involved 15 areas/countries. Global birth prevalence of Pompe disease was 2.0 cases (95% CI: 1.5–2.4) per 100,000 live births. Global birth prevalence of infantile-onset Pompe disease was 1.0 cases (95% CI: 0.5–1.5) per 100,000 live births. Global birth prevalence of late-onset Pompe disease was 2.4 cases (95% CI: 1.8–3.0) per 100,000 live births. The main limitations are that no study was assessed as high-quality and approximately half of the studies were from Europe. ConclusionsQuantitative data on the global epidemiology of Pompe disease could be the fundamental to evaluate the global efforts on building a better world for Pompe disease patients.

Screening for late-onset Pompe disease in Internal Medicine departments in Spain

BackgroundThe screening of high-risk populations using dried blood spots (DBS) has allowed the rapid identification of patients with Pompe disease, mostly in Neurology departments. The aim of the study was to determine the prevalence of late-onset Pompe disease (LOPD) among patients not previously diagnosed or tested for this entity despite presenting possible signs or symptoms of the disease in Internal Medicine departments in Spain.MethodsThis epidemiological, observational, cross-sectional, multicenter study included a single cohort of individuals with clinical suspicion of LOPD seen at Internal Medicine departments in Spain. The diagnosis of LOPD was initially established on the basis of the result of DBS. If decreased enzyme acid-alpha-1,4-glucosidase (GAA) activity was detected in DBS, additional confirmatory diagnostic measurements were conducted, including GAA activity in lymphocytes, fibroblasts, or muscle and/or genetic testing.ResultsThe diagnosis of LOPD was confirmed in 2 out of 322 patients (0.6%). Reasons for suspecting LOPD diagnosis were polymyositis or any type of myopathy of unknown etiology (in one patient), and asymptomatic or pauci-symptomatic hyperCKemia (in the other). The time between symptom onset and LOPD diagnosis was 2.0 and 0.0 years. Both patients were asymptomatic, with no muscle weakness. Additionally, 19.7% of the non-LOPD cases received an alternative diagnosis.ConclusionsOur study highlights the existence of a hidden population of LOPD patients in Internal Medicine departments who might benefit from early diagnosis and early initiation of potential treatments.

Model-Informed Approach Supporting Approval of Nexviazyme (Avalglucosidase Alfa-ngpt) in Pediatric Patients with Late-Onset Pompe Disease.

In August 2021, the US Food and Drug Administration approved Nexviazyme (avalglucosidase alfa-ngpt) for intravenous infusion to treat patients 1year of age and older with late-onset Pompe disease (LOPD). The effectiveness and safety were studied in patients with LOPD and patients with infantile-onset Pompe disease (IOPD). The dosage(s) tested in clinical trials was 20mg/kg every other week (qow) in patients with LOPD and 20mg/kg and 40mg/kg qow in patients with IOPD. While patients 3years old and greater with LOPD were eligible for participation in the pivotal trial, the youngest patient enrolled was 16years old. Therefore, pediatric patients with LOPD were not well represented in the clinical trial. The prevalence of LOPD in pediatrics is extremely low. Thus, conducting a clinical trial in pediatric patients with LOPD would be challenging. Given the similar pathophysiology, mechanism of action, and disease manifestations across the age spectrum of patients with LOPD, the approved dosages for pediatric patients younger than 16years old with LOPD were based on extrapolation of efficacy using a model-informed exposure bridging strategy, leveraging the safety data from pediatric patients with IOPD. Specifically, the exposure associated with 20mg/kg qow in adult patients with LOPD was the target exposure for bridging of efficacy. The safety data obtained with 40mg/kg qow in patients with IOPD was leveraged to support approval in pediatric patients with LOPD aged 1year and older. This article illustrates a regulatory use of model-informed extrapolation approach for dose selection in pediatric patients with a rare disease.

Investigating Late-Onset Pompe Prevalence in Neuromuscular Medicine Academic Practices: The IPaNeMA Study.

Background and ObjectivesWe investigated the prevalence of late-onset Pompe disease (LOPD) in patients presenting to 13 academic, tertiary neuromuscular practices in the United States and Canada.MethodsAll successive patients presenting with proximal muscle weakness or isolated hyperCKemia and/or neck muscle weakness to these 13 centers were invited to participate in the study. Whole blood was tested for acid alpha-glucosidase (GAA) assay through the fluorometric method, and all cases with enzyme levels of ≤10 pmoL/punch/h were reflexed to molecular testing for mutations in the GAA gene. Clinical and demographic information was abstracted from their clinical visit and, along with study data, entered into a purpose-built REDCap database, and analyzed at the University of California, Irvine.ResultsGAA enzyme assay results were available on 906 of the 921 participants who consented for the study. LOPD was confirmed in 9 participants (1% prevalence). Another 9 (1%) were determined to have pseudodeficiency of GAA, whereas 19 (1.9%) were found to be heterozygous for a pathogenic GAA mutation (carriers). Of the definite LOPD participants, 8 (89%) were Caucasian and were heterozygous for the common leaky (IVS1) splice site mutation in the GAA gene (c -32-13T>G), with a second mutation that was previously confirmed to be pathogenic.DiscussionThe prevalence of LOPD in undiagnosed patients meeting the criteria of proximal muscle weakness, high creatine kinase, and/or neck weakness in academic, tertiary neuromuscular practices in the United States and Canada is estimated to be 1%, with an equal prevalence rate of pseudodeficiency alleles.Trial Registration InformationClinical trial registration number: NCT02838368.

Potential patient screening for late-onset Pompe disease in suspected sleep apnea: a rationale and study design for a Prospective Multicenter Observational Cohort Study in Japan (PSSAP-J Study).

Pompe disease is an autosomal recessive disorder caused by deficiency of the acid α-glucosidase (GAA) enzyme. GAA deficiency induces progressive glycogen accumulation which leads to weakness of the respiratory muscle including the diaphragm. Pompe disease is one of the few myopathies, for which an established therapy is available. Thus, earlier detection of potential late-onset Pompe disease (LOPD) and earlier intervention would have a significant clinical impact. Our hypothesis is that sleep problems including sleep disordered breathing (SDB) and clinical symptoms may indicate an early stage of LOPD since decreased respiratory muscle activity generally first presents during sleep. Thus, the aims of this prospective, multicenter observational cohort study in Japan (PSSAP-J) are to demonstrate a higher prevalence of LOPD in a sleep lab-based population (primary outcome), and to identify predictive factors for LOPD from findings in diagnostic polysomnography (PSG) and clinical symptoms (secondary outcomes). The study design is a prospective multicenter observational cohort study. Consecutive patients who present to sleep labs due to suspected SDB for an overnight PSG will be enrolled. All patients will be measured for creatine kinase, GAA activity, and if necessary, genetic analysis of GAA. Furthermore, chest X-ray, pulmonary function test, and arterial blood gas analysis will be collected. Then, prevalence and specific findings of LOPD will be assessed. Congenital myopathy shows a shift from slow-deep to rapid-shallow breathing during transition from wakefulness to sleep accompanying a symptom of waking with gasping (actual further results are pending). The distribution in respiratory physiology between during wakefulness and sleep specific to LOPD may provide insights into early-stage detection. UMIN000039191, UMIN Clinical Trials Registry ( http://www.umin.ac.jp/ctr ).

Selective screening of late-onset Pompe disease (LOPD) in patients with non-diagnostic muscle biopsies

AimsAs of 2016, there were five patients with Pompe in Slovenia (two infantile, one childhood and two adult onset) with a prevalence of 1:400 000; however, the prevalence of late-onset...

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

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.

Evaluation prevalence of Pompe disease in Iranian patients with myopathies of unknown etiology.

BackgroundPompe disease is a rare but potentially treatable metabolic disorder having an estimated worldwide incidence of one in forty thousand live births. While the introduction of enzyme replacement therapy (ERT) has considerably increased the awareness of the disease, the delay in diagnosis is still consistent and most patients go undetected.ObjectiveThis study aimed to determine the prevalence of late-onset Pompe disease (LOPD) in a high-risk population, using dried blood spot (DBS) as a main screening tool.MethodsThis cross-sectional study was performed on the 93 patients who attended to the neuromuscular center of Bu-ali hospital in Tehran, Iran, during 2014–2015. Inclusion criteria were: 1) age ≥1 years, 2) proximal myopathies of unknown etiology in lower limbs or symptoms of limb girdle muscle weakness (LGMW), and 3) unexplained elevated CPK (>174). Acid α-glucosidase (GAA) activity was measured separately on DBS by fluorometric method. For the final diagnosis, GAA deficiency was confirmed by a biochemical assay in skeletal muscle, whereas genotype was assessed by GAA molecular analysis. All statistical tests were performed using the SPSS version 16. Results are presented as mean (SD) or median (IQR), as appropriate.ResultsIn a 12-month period, we studied 93 cases: 5 positive samples (5.3%) were detected by DBS screening, biochemical and molecular genetic studies finally confirmed LOPD diagnosis in 3 cases (3.22%). Among the 93 patients, 100% showed hyperCKemia, 89 patients (95.7%) showed LGMW and 4 patients had symptoms of proximal myopathies in the lower limb.ConclusionsResults from the LOPED study suggest that GAA activity requires accurate screening by DBS in all patients referred for hyperCKemia and/or LGMW.

Prevalence of late-onset pompe disease in Portuguese patients with diaphragmatic paralysis – DIPPER study

Pompe disease is a rare autosomal recessive neuromuscular disorder caused by acid α-glucosidase enzyme (GAA) deficiency and divided into two distinct variants, infantile- and late-onset. The late-onset variant is characterized by a spectrum of phenotypic variation that may range from asymptomatic, to reduced muscle strength and/or diaphragmatic paralysis. Since muscle strength loss is characteristic of several different conditions, which may also cause diaphragmatic paralysis, a protocol was created to search for the diagnosis of Pompe disease and exclude other possible causes. MethodsWe collected a sample size of 18 patients (10 females, 8 males) with a median age of 60 years and diagnosis of diaphragmatic paralysis of unknown etiology, followed in the Pulmonology outpatient consultation of 9 centers in Portugal, over a 24-month study period. We evaluated data from patient's clinical and demographic characteristics as well as complementary diagnostic tests including blood tests, imaging, neurophysiologic and respiratory function evaluation. All patients were evaluated for GAA activity with DBS (dried blood test) or serum quantification and positive results confirmed by serum quantification and sequencing. ResultsThree patients were diagnosed with Pompe's disease and recommended for enzyme replacement therapy. The prevalence of Pompe, a rare disease, in our diaphragmatic paralysis patient sample was 16.8%. ConclusionWe conclude that DBS test for GAA activity should be recommended for all patients with diaphragmatic paralysis which, despite looking at all the most common causes, remains of unknown etiology; this would improve both the timing and accuracy of diagnosis for Pompe disease in this patient population. Accurate diagnosis will lead to improved care for this rare, progressively debilitating but treatable neuromuscular disease.

Prevalence of Pompe disease in 3,076 patients with hyperCKemia and limb-girdle muscular weakness.

We prospectively screened a large European cohort of patients presenting with hyperCKemia and/or limb-girdle muscular weakness (LGMW) for acid α-glucosidase (GAA) deficiency by dried blood spot (DBS) investigation. DBS were collected from 3,076 consecutive adult patients from 7 German and British neuromuscular centers. All specimens were investigated for GAA deficiency by fluorometry. Samples with reduced enzyme activity were subsequently investigated for GAA gene mutations. Of 3,076 patients with DBS samples, 232 patients (7.6%) showed low GAA enzyme activity. Of these 232 patients, 55 (24%) presented with isolated hyperCKemia and 176 (76%) with hyperCKemia and LGMW. With both features present, 94% of the patients showed a low enzymatic activity. Mutational analysis found GAA gene mutations in 74 patients (2.4%); herein 70 patients were heterozygote for the common GAA gene splice-site mutation c.-32-13T>G. The most common clinical presentation in the confirmed Pompe cohort was a limb-girdle phenotype (85.3%) combined with ventilatory insufficiency (61%). Isolated hyperCKemia was found in 12%, while 2.7 had hyperCKemia and ventilatory insufficiency only. In a large cohort of unselected adult patients with hyperCKemia and/or LGMW, we found a prevalence of late-onset Pompe disease of 2.4%. Therefore, targeted screening of such a population should be encouraged in clinical practice.

LOPED study: looking for an early diagnosis in a late-onset Pompe disease high-risk population

ObjectiveA multicentre observational study was aimed to assess the prevalence of late-onset Pompe disease (LOPD) in a large high-risk population, using the dried blood spot (DBS) as a main screening...

The Incidence of Late-Onset Pompe Disease in Subjects with Obstructive Sleep Apnea: A Cross-Sectional Study

Objectives: Current treatment options for obstructive sleep apnea syndrome often work to the sa-tisfaction of the patient, but in certain cases may not yield the required results for reasons that remain unclear. Late-onset Pompe disease may be a contributing factor in these circumstances. The aim of the present study was to determine the incidence of late-onset Pompe disease in a population diagnosed with obstructive sleep apnea. Material and Methods: The study had a cross-sec- tional, explorative design to assess the prevalence of late-onset Pompe disease in subjects with an established diagnosis of obstructive sleep apnea syndrome. In two different study mid to large size sleep clinics in Europe patients have been asked to donate a blood sample for the detection of ac-id-glucosidase enzyme activity. Results: Of a total of 544 patients with mild to severe obstructive sleep apnea, none had an acid maltase deficiency. Conclusions: Screening for Pompe disease in newly or recently detected OSA patients in mid to large size sleep clinics is not clinically effective. It should be confined to those subjects with OSA when upright forced vital capacity during spirometry is only moderately abnormal, because of the disproportionate diaphragmatic involvement.