A new phenotype of infantile-onset Pompe disease
Introduction. Infantile-onset Pompe disease is a kind of glycogenosis resulting from a deficit of the enzyme acid alpha-glucosidase. Before specific enzyme replacement therapy (ERT) became available, the classic form was fatal during the first two years of life. ERT increases survival and improves cardiac, respiratory and motor functioning.
Case reports. Case 1: 2-month-old infant with predominantly axial hypotonia who required the use of a nasogastric tube as a result of difficulties in sucking and swallowing. Myopathy and hypertrophic cardiomyopathy were observed. The patient was diagnosed with Pompe disease, ERT was established and improved heart and motor functioning were noted. Nevertheless, she presented recurring respiratory infections that finally made it necessary to perform a tracheostomy. She is currently still undergoing ERT, walks with a walker and presents a mild ventricular dysfunction. Case 2: 3-week-old infant who was taken to see his paediatrician for a routine check-up. The examination revealed a systolic bruit and axial and proximal hypotonia. Cardiology tests revealed hypertrophic cardiomyopathy. The patient was sent to a referral centre, where he was diagnosed with Pompe disease and a cross-reactive immunological material-negative status. The patient received immunomodulator treatment and ERT. Progress was favourable, although he presented frequent respiratory infections. The patient is currently capable of walking by himself, although the gait is unsteady.
Conclusions. Both cases illustrate the new phenotype of infantile-onset Pompe disease treated with ERT. Despite the motor limitations and respiratory involvement presented by the patients, both survival and autonomy have increased.
Key words. Acid alpha-glucosidase. CRIM status. Enzyme replacement therapy. Hypertrophic cardiomyopathy. Hypotonia. Pompe disease.