SEVERELY HYPOTONIC BABY WITH FAILURE TO THRIVE

Aim
Pompe disease is rare, progressive and fatal neuromuscular disorder. It is caused by a deficiency of lysosomal alpha-glucosidase, resulting in lysosomal glycogen accumulation in multiple tissues, with cardiac and skeletal muscles being the most seriously affected. Incidence may vary from 1 in 14, 000 to 1 in 300, 000. Patient presented with respiratory distress due to heart failure.

Sample and Methodology
Baby age 6 month has been admitted to Royal Free Hospital. Baby was floppy, no head control. Deep tendon reflexes could not be elicited. Cardiovascular examination revealed normal first and second heart sounds. Gallop rhythm. Liver edge at 3cm below the right costal margin. Failure to thrive, below 0.4centile.
Parents are first cousins on maternal side. Family history of 2 infant deaths in extended family for possible cardiac problems – unclear aetiology.
Results
Chest XR: prominent cardiac silhouette.
ECHO:  Biventricular hypertrophy with poor ventricular function. No outflow obstruction.

12 lead ECG:  Sinus rhythm. Biventricular hypertrophy, ST segment depression.
EMG: Normal nerve conduction, no evidence of neuropathy.

Brain MRI: No structural or focal abnormality of the brain.
Reduced serum Acid-Alpha-Glucosidase (GAA) activity on dried blood spot screening was suggestive of infantile onset Pompe disease. On quantitative analysis of GAA, there was complete absence of enzyme activity.
Conclusion
In the classic infantile form onset of symptoms is at the median age of 1.6 months with the majority of patients dying at the median age of 6 – 7.7 months. In the last few years the world of metabolic myopathies has been dramatically modified by the advent of enzyme replacement therapy. The patient has been started on the current protocol of enzyme replacement therapy GOSH, clinically slowly improving. We report the progress in details.