Late Onset Pompe's Disease: Clinical, Pathological & Molecular Analysis of Two Adolescent Patients.

INTRODUCTION:The estimated global prevalence of late onset Pompe's disease is 1/57000 live birth(1). We present the case of two patients diagnosed to have Pompe's disease with a rare association of cardiomyopathy.MATERIALS:Two siblings born out of non consanguineous marriage presented with proximal myopathy of 5 years duration. Patient 1 - 19 year female, there was atrophy and weakness of face, neck, girdle and limbs. Her Echocardiogram showed LV dilation with low ejection fraction, ECG showed LV hypertrophy with incomplete LBBB. Her CK-NAC values came to be 918 U/L. Patient 2 - 16 year male; progression, distribution and severity slightly different to his sister but had exertional dyspnea since last one year. His echocardiogram showed LV diastolic dysfunction, ECG showed short PR interval partial LBBB and his CK-NAC came to be 2347 U/L. His skeletal muscle biopsy showed deposition of glycogen. Genetic analysis revealed pathogenic mutation in GAA gene (c.2040G>A) in both patients.RESULT:Late onset Pompe disease is of less severity but progressive. The involvement of heart is less likely compared to infantile onset(2). It is also interesting that the same variant presents differently in both patients.CONCLUSION:Genetic diseases manifest as rare phenotype which in itself is a clinical puzzle. When rare disease present with a rare manifestation of itself, this pose a great diagnostic challenge. Pompe's disease is one of the very few inherited disorder which has definitive treatment- enzyme replacement therapy. Molecular characterization of the variant is absolutely necessary before initiating therapy. References Ausems MG, Verbiest J, Hermans MM, et al. Frequency of glycogen storage disease type II in The Netherlands: implications for diagnosis and genetic counselling. Eur J Hum Genet 1999;7(6):713-716. Van der Beek NA, Soliman OI, Van Capelle CI, et al. Cardiac evaluation in children and adults with Pompe disease sharing the common c.-32-13T>G genotype rarely reveals abnormalities. J Neurol Sci 2008;275(1-2):46-50.