Global variations in diagnostic methods and epidemiological estimates in Pompe disease: findings from a scoping review.

Background: Pompe disease is caused by pathogenic variants in the GAA gene, resulting in lysosomal acid α-glucosidase (GAA) deficiency. The prevalence of Pompe disease is not well-defined, and estimates vary by geographic region. We evaluated the global epidemiology of Pompe disease and the potential reasons for differing prevalence estimates using published data from worldwide newborn screening (NBS) programs and population-based studies.

Methods: A comprehensive literature search in PubMed was conducted in July 2023, updated in March 2024, and validated with an Embase search in June 2024. Search terms included Pompe disease, GSDII, prevalence, incidence, epidemiology, survival, mortality, and NBS. Studies were included based on robust epidemiological methods, the presence of disease definition, and publication within the past 5 years. We identified 1210 abstracts, of which 295 met recency criteria, 30 were deemed relevant, and 11 met all inclusion criteria.

Results: Prevalence estimates and GAA enzyme activity cutoff values varied across geographic regions. In NBS studies, the birth prevalence of infantile-onset Pompe disease (IOPD) ranged from 1 in 297,387 in Japan to 1 in 62,186 in Taiwan, and late-onset Pompe disease (LOPD) ranged from 1 in 82,914 in Taiwan to 1 in 17,133 in Pennsylvania. Data from the French National Pompe Registry (N = 246) showed an increase in diagnosis of LOPD from 2.6/year before 2001 to 10.6/year during 2001-2010 and 12.8/year during 2011-2015. Enzyme cutoffs in dried blood spots varied from < 3% of lymphocyte mean to 2.10 μmol/L/h to ≤ 18% of the daily median. Three studies noted higher prevalence in populations of African descent, and two noted a higher frequency of pseudodeficiency alleles in Asian populations.

Conclusions: This scoping review confirmed that prevalence estimates differ for IOPD and LOPD and vary by geographic region, potentially by race and ethnicity. It highlights the need to standardize screening and diagnosis methods, genetic testing protocols, and uniform disease classification between IOPD and LOPD.