title: Reevaluating Muscle Biopsies in the Diagnosis of Pompe Disease: A Corroborative Report.
abstract: BACKGROUND
  Previous reports suggest that although a diagnostic muscle biopsy can confirm the presence of Pompe disease, the absence of a definitive biopsy result does not rule out the diagnosis.
  
  
  METHODS
  In this study, we reviewed patients with a limb-girdle syndrome who demonstrated nonspecific abnormalities of muscle, without evidence of the classical changes of acid maltase deficiency. These patients were rescreened for Pompe disease using dried blood spot (DBS) testing.
  
  
  RESULTS
  Twenty-seven patients provided blood samples for the DBS test. Four patients underwent subsequent genetic testing. Genetic analysis demonstrated that one patient tested positive for Pompe disease and one patient had one copy of a pathogenic variant.
  
  
  CONCLUSIONS
  In conclusion, the ability of a diagnostic muscle biopsy to definitively rule out the presence of Pompe disease is limited. There is a role for a screening DBS in all patients presenting with a limb-girdle syndrome without a clear diagnosis.
authors.affiliation: 1Department of Neurology and Neurosurgery,Montreal Neurological Institute and Hospital,McGill University Health Centre,Montreal,QC,Canada.
authors.forename: Angela
authors.initials: A
authors.lastname: Genge
authors.affiliation: 2Clinical Research Unit,Montreal Neurological Institute and Hospital,McGill University Health Centre,Montreal,QC,Canada.
authors.forename: Natasha
authors.initials: N
authors.lastname: Campbell
mesh_terms: D000328:Adult; D001706:Biopsy; D005260:Female; D005820:Genetic Testing; D006009:Glycogen Storage Disease Type II / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000201:enzymology / Q000473:pathology*; D012189:Retrospective Studies; D018911:Trinucleotide Repeats / Q000235:genetics; D000520:alpha-Glucosidases / Q000235:genetics / Q000378:metabolism
chemical_list: C509951:GAA protein, human; D000520:alpha-Glucosidases
keywords: Acid maltase deficiency; Dry blood spot; Glycogen storage disease; Muscle biopsy; Pompe disease