Study objective and method
Examine patients with LGMW and/or hyperCKemia and undiagnosed muscle biopsy for LOPD
Inclusion criteria: Inconclusive LGMW with undiagnosed muscle biopsies
evaluated muscle biopsies,
activity of GAA
Median DBS GAA activity: 1.18 nmol/punch×21 hours
Reduced GAA activity was identified through enzyme kinetic testing in two patients
A 22-year–old Caucasian female with the chief complaint of muscular exertion intolerance associated with muscle aches and cramps.
A 29-year–old Caucasian male with atrophies of the shoulder, pelvic girdle, and paravertebral muscles. Predominantly left-sided scapula alata and positive Gower’s sign.
Completely unspecific myopathic changes with evidence of small lipid droplets
• Suspicious changes associated with Pompe disease
• Vacuolated muscle fibers
• Glycogen storage with enhanced lysosomal activity
No signs of HCM, FVC: <80%
No signs of HCM, FVC: 72%
Revisiting muscle biopsies is important in neuromuscular disease diagnosis.
Muscle biopsy can aid in LOPD identification, but glycogen-related vacuolation can be absent.
An inconclusive muscle biopsy does not rule out Pompe disease.
DBS evaluation should precede muscle biopsy for all LGMW patients
ALAT: Alanine aminotransferase; AST: Aspartate transaminase; CK: Creatine kinase; DBS: Dried blood spots; FVC: Forced vital capacity; HCM: Hypertrophic cardiomyopathy; LGMW: Limb-girdle myopathic weakness; LOPD: Late-onset Pompe disease.
Golsari A, Nasimzadah A, Thomalla G, et al. Prevalence of adult Pompe disease in patients with proximal myopathic syndrome and undiagnosed muscle biopsy. Neuromuscul Disord. 2018;28(3):257–261.
MAT-KW-2300241 V1 Jul 2023