Neuromuscular diseases have a great phenotypic variability and sometimes nonspecific clinical variations, requiring diagnostic confirmation with genetic testing. Proximal muscle weakness and elevated CK levels are present in several myopathies, as well as in Pompe disease. The aim of the study was to evaluate the symptomatology and severity of late Pompe disease in patients with proximal muscle weakness and elevated CK. In a cohort of 48 patients the NGS panel was performed for the genes: ANO5, DYSF, GAA, SGCB, SGCG, CAPN3, FKRP, SGCA, SGCD and TCAP. Of the total, 18(37,7%) were diagnosed: CAPN3 5(10,4%), DYSF 5(10,4%), GAA 3(6,3%), FKRP 2(4,2%), TCAP 2(4,2%) and ANO5 1(2,1%). Clinical findings in patients with late-onset Pompe: childhood onset (3), axial muscle weakness (3), facial weakness (2), respiratory failure (2) and dysphagia (1). Laboratorial exams: average CK level (1047 U/L), myopathic electroneuromyography (3), spirometric alterations (3), GAA c.-32-13 T>G variant (2), GAA c.32-3 C>A(1), vacuolar myopathy (1), nonspecific myopathic alterations(1). The percentage of genetic diagnoses made indicates that the NGS panel is restricted, despite its high specificity. In our study, the prevalence of 6.3% for late Pompe disease was established in patients with proximal muscle weakness and elevated CK. There are different data in the literature about the prevalence of this disease: 2.5% in Europe, 4.2% in Brazil and 0.8% in the United States. There was a great variability of the prevalence found, which may be the result of epigenetic aspects and methodological variations between the studies. The fact that one of the patients did not present typical alterations of the disease in the biopsy and a normal spirometry shows that the negative result of these exams does not rule out the possibility of the diagnosis in patients with proximal muscle weakness and elevated CK.