Investigating Late-Onset Pompe Prevalence in Neuromuscular Medicine Academic Practices: The IPaNeMA Study

Marie Wencel; Aziz Shaibani; Namita A Goyal; Mazen M Dimachkie; Jaya Trivedi; Nicholas E Johnson; Laurie Gutmann; Matthew P Wicklund; Sankar Bandyopadhay; Angela L Genge; Miriam L Freimer; Neelam Goyal; Alan Pestronk; Julaine Florence; Chafic Karam; Jeffrey W Ralph; Zinah Rasheed; Melissa Hays; Steve Hopkins; Tahseen Mozaffar

doi:10.1212/NXG.0000000000000623

Investigating Late-Onset Pompe Prevalence in Neuromuscular Medicine Academic Practices: The IPaNeMA Study

Neurol Genet. 2021 Oct 18;7(6):e623. doi: 10.1212/NXG.0000000000000623. eCollection 2021 Dec.

Authors

Marie Wencel¹, Aziz Shaibani¹, Namita A Goyal¹, Mazen M Dimachkie¹, Jaya Trivedi¹, Nicholas E Johnson¹, Laurie Gutmann¹, Matthew P Wicklund¹, Sankar Bandyopadhay¹, Angela L Genge¹, Miriam L Freimer¹, Neelam Goyal¹, Alan Pestronk¹, Julaine Florence¹, Chafic Karam¹, Jeffrey W Ralph¹, Zinah Rasheed¹, Melissa Hays¹, Steve Hopkins¹, Tahseen Mozaffar¹

Affiliation

¹ Department of Neurology (M.W., N.A.G., T.M.), University of California, Irvine; Nerve and Muscle Center of Texas (A.S., Z.R.), Houston, TX; Department of Neurology (M.M.D., M.H.), University of Kansas Medical Center; Department of Neurology and Neurotherapeutics (J.T., S.H.), University of Texas Southwestern, Dallas; Department of Neurology (N.E.J.), Virginia Commonwealth University, Richmond (affiliated with University of Utah, Salt Lake City at the Time of Study); Department of Neurology (L.G.), Indiana University School of Medicine, Indianapolis (affiliated with University of Iowa at the Time of Study); Department of Neurology (S.B.), Pennsylvania State University, Hershey; Department of Neurology (M.P.W.), UC Denver, CO (affiliated with Department of Neurology, Pennsylvania State University, Hershey at the Time of the Study); Department of Neurology and the Montreal Neurological Institute (A.L.G.), McGill University, Montreal, Quebec, Canada; Department of Neurology (M.L.F.), Ohio State University, Columbus; Department of Neurology (N.G.), Stanford University, Palo Alto, CA; Department of Neurology and Pathology (A.P., J.F.), Washington University, St. Louis, Missouri; Department of Neurology (A.P., C.K.), University of Pennsylvania, Philadelphia (affiliated with Oregon Health & Science University, Portland at the Time of Study); Department of Neurology (J.W.R.), University of California, San Francisco; and Departments of Neurology (T.M.), Orthopaedic Surgery and Pathology and Laboratory Medicine, University of California, Irvine.

Abstract

Background and objectives: We investigated the prevalence of late-onset Pompe disease (LOPD) in patients presenting to 13 academic, tertiary neuromuscular practices in the United States and Canada.

Methods: All successive patients presenting with proximal muscle weakness or isolated hyperCKemia and/or neck muscle weakness to these 13 centers were invited to participate in the study. Whole blood was tested for acid alpha-glucosidase (GAA) assay through the fluorometric method, and all cases with enzyme levels of ≤10 pmoL/punch/h were reflexed to molecular testing for mutations in the GAA gene. Clinical and demographic information was abstracted from their clinical visit and, along with study data, entered into a purpose-built REDCap database, and analyzed at the University of California, Irvine.

Results: GAA enzyme assay results were available on 906 of the 921 participants who consented for the study. LOPD was confirmed in 9 participants (1% prevalence). Another 9 (1%) were determined to have pseudodeficiency of GAA, whereas 19 (1.9%) were found to be heterozygous for a pathogenic GAA mutation (carriers). Of the definite LOPD participants, 8 (89%) were Caucasian and were heterozygous for the common leaky (IVS1) splice site mutation in the GAA gene (c -32-13T>G), with a second mutation that was previously confirmed to be pathogenic.

Discussion: The prevalence of LOPD in undiagnosed patients meeting the criteria of proximal muscle weakness, high creatine kinase, and/or neck weakness in academic, tertiary neuromuscular practices in the United States and Canada is estimated to be 1%, with an equal prevalence rate of pseudodeficiency alleles.

Trial registration information: Clinical trial registration number: NCT02838368.

Associated data

ClinicalTrials.gov/NCT02838368