Late onset form of Pompe disease

Background: Pompe disease is an autosomal recessive disorder of glycogen metabolism caused by deficiency in lysosomal enzyme α-glucosidase.

Objectives: We present first two patients from Slovakia with confirmed Pompe disease.

Methods: Activity of α-glucosidase was measured using 4-methylumbelliferyl-α-D-glucopyranoside with the presence of acarbose, inhibitor that eliminates isoenzyme interference of maltase-glucoamylase. This methodical approach is substantial for determination of lysosomal enzyme deficiency. Using molecular genetic methods, PCR-RFLP and direct sequencing of coding region α-glucosidase gene (GAA) we have identified causal mutations in our patients.

Results: Late-onset type of disease was confirmed by measuring α-glucosidase activity in leukocytes isolated from blood. The presence of common Caucasian mutation c.-32-13T>G was proved by genetic testing in the first patient in homozygous state. Second patient was a compound heterozygote, with mutation c.-32-13T>G on one allele and mutation A486P on the second allele.

Conclusion: We present a diagnostic algorithm for diagnosing the Pompe disease in patients of European origin. Enzyme replacement therapy has been used as a treatment option for improving the quality of life of patients. Early diagnosis and treatment of Pompe disease are considered to be critical for maximum efficacy of enzyme replacement therapy (Tab. 1, Fig. 3, Ref. 20).