G.P.255: Epidemiology and screening of Pompe disease in Sweden

Abstract

Pompe disease (acid maltase deficiency or glycogen storage disease type II) is an autosomal-recessive inherited and potentially treatable metabolic myopathy with heterogeneous clinical presentations and with considerable overlap of signs and symptoms with other neuromuscular disorders. According to previous reports, patients with Pompe disease have often been incorrectly diagnosed as limb-girdle muscular dystrophy (LGMD). To diagnose both entities is challenging and a diagnostic delay of several years is common. The frequency of misdiagnosis is unknown. Epidemiologic studies on Pompe disease have not been done in the nordic countries. This is the first, registry-based, study on epidemiology of Pompe disease in Sweden. First, we identified all patients with Pompe disease by validating retrospectively the diagnosis using the medical records of individuals with the unspecified diagnosis code E74.0 (glycogen storage diseases) according to the International Classification of Diseases version 10 (ICD-10). Beyond this, we selected from the National Patient Registry all in-and outpatients in Sweden with genetically unclassified LGMD and limb-girdle muscle weakness and then screened for Pompe disease by enzyme analysis on dried blood spots. Hereby, we report the preliminary results of the screening study and data on the prevalence of Pompe disease in Sweden.