T.P.22: Two cases of late-onset Pompe disease treated with enzyme replacement therapy: Clinical outcome for 3 years follow-up

Abstract

Pompe disease is a progressive neuromuscular disorder, caused by an inherited deficiency of acid alpha-glucosidase (GAA). Treatment of pompe disease with enzyme replacement therapy (ERT) may reverse, stabilize or slow disease progression. We present 2 cases of Late-onset pompe disease (LOPD) treated with ERT for about 3years. Case 1: A 33-year-old man was admitted in our hospital for dyspnea. At 16years old, He felt progressive weakness of his lower limbs. At 18years old, He felt tiredness when he climbed the stairs. At 29years old, he had mild respiratory difficulty. At 33years old, he admitted in our hospital and showed proximal weakness, low forced vital capacity (FVC) and elevated creatine kinase (CK) level. On dried blood spot (DBS) test and molecular analysis, low GAA activity and two mutations (c.1309C>T, c.1316T>A) were detected. He applied non-invasive positive pressure ventilation (NIPPV) and treated with ERT for 3years. For two years with ERT, he can walk without assistance for some minutes and his other symptoms were improved. But, for 3rd year with ERT, symptoms were slightly deteriorated and he could not walk without assistance beyond 5min. Case 2: A 53-year-old woman was admitted with slowly progressive proximal weakness of the lower limbs. At 12years old, she had difficulty climbing stairs. At 47years old, she experienced breathing difficulty in the supine position. At 48years old, she admitted to hospital to evaluate her weakness and use the NIPPV. She showed proximal weakness, low FVC and normal CK level. On DBS test and molecular analysis, low GAA activity and two mutations (c.1316T>A, c.2238G>C) were detected. After 3years of ERT treatment, she presented slightly improved clinical course. After three years, she can walk without assistance beyond 500 meters and use NIPPV during only sleep. Our findings show that ERT had a stabilized or improving therapeutic effect of neuromuscular deficits in LOPD patients during 3years of ERT.