[Variability in the clinical presentation of Pompe disease in infancy: two case reports and response to treatment with human recombinant enzyme].

INTRODUCTION: Pompe disease/glycogen storage disease type II is a congenital metabolic disorder. It is an autosomal recessive disease where there is a deficiency of acid alpha-glucosidase (GAA), an enzyme required for lysosomal glycogen degradation. We describe two infantile onset cases with heterogeneous presentations.

CASE REPORTS: The first case is a newborn with maintained bradycardia, a cardiologic study revealed severe biventricular hypertrophy. The second case is a 14 months old patient with motor delay and arreflexic hypotonia. Creatine kinase, lactate dehydrogenase, glutamic-oxaloacetic transaminase and glutamic-pyruvic trans aminase were high. The electromyogram showed myopathic alteration and the muscle biopsy vacuolar myopathy with glycogen accumulation. In both of them, GAA activity was decreased and the genetic exam of the GAA gene revealed heterozygous mutations already described in Pompe disease. They started enzyme replacement therapy at 1 month old and 18 months old respectively, improving the cardiomyopathy hypertrophy, motor wise however less advance was seen. At the present time, the patients are 9 months and 5 years old respectively, the last one has a Gross Motor Function Measure (GMFM) III level.

CONCLUSION: GAA is the only authorized option for Pompe disease treatment; the effects observed are similar to the ones described in the literature, with excellent outcome in the hypertrophic cardiomyopathy but less effective in the skeletal muscle.