Development of a feasible assay for the detection of GAA mutations in patients with Pompe disease

Abstract

Background: Pompe disease is an inherited autosomal recessive deficiency of acid alpha-glucosidase (GAA) and is due to pathogenic sequence variants in the corresponding GM gene. While the analysis of enzyme activity remains the diagnostic test of choice for individuals with Pompe disease, mutation analysis remains for establishing a definitive diagnosis. Methods: High resolution melting (HRM) analysis was performed to screen GM mutations. Genomic DNA was extracted from peripheral blood samples of the two patients with Pompe disease and 250 normal controls. Exons 2 through 20 of the GM gene were screened by the HEM analysis. The results were subsequently confirmed by direct sequencing. Results: This assay proved to be feasible in detecting seven known (c2T>C, c.1726G>A, c.1845G>A, c.1935C>A, c.1958C>A, c.2238G>C, and c2815_2816del) GM mutations. Each mutation could be readily and accurately identified in the difference plot curves. We estimated the carrier frequency of the most common mutation, c.1935G>A (p.D645E), in the Taiwanese population to be 02%. Conclusions: In clinical practice, we suggest that HEM analysis is assumed as a fast and reliable method for screening GM gene mutations especially the most common mutations which are responsible for Pompe disease among the Taiwanese populations. (C) 2013 Elsevier B.V. All rights reserved.