title: Late-Onset Glycogen Storage Disease Type II (Pompe's Disease) with a Novel Mutation: A Malaysian Experience.
abstract: Pompe's disease (acid maltase deficiency, glycogen storage disease type II) is an autosomal recessive disorder caused by a deficiency of lysosomal acid α-1,4-glucosidase, resulting in excessive accumulation of glycogen in the lysosomes and cytoplasm of all tissues, most notably in skeletal muscles. We present a case of adult-onset Pompe's disease with progressive proximal muscles weakness over 5 years and respiratory failure on admission, requiring prolonged mechanical ventilation. Electromyography showed evidence of myopathic process with small amplitudes, polyphasic motor unit action potentials, and presence of pseudomyotonic discharges. Muscle biopsy showed glycogen-containing vacuoles in the muscle fibers consistent with glycogen storage disease. Genetic analysis revealed two compound heterozygous mutations at c.444C>G (p.Tyr148∗) in exon 2 and c.2238G>C (p.Trp746Cys) in exon 16, with the former being a novel mutation. This mutation has not been reported before, to our knowledge. The patient was treated with high protein diet during the admission and subsequently showed good clinical response to enzyme replacement therapy with survival now to the eighth year. Conclusion. In patients with late-onset adult Pompe's disease, careful evaluation and early identification of the disease and its treatment with high protein diet and enzyme replacement therapy improve muscle function and have beneficial impact on long term survival.
authors.affiliation: Department of Neurology, Kuala Lumpur General Hospital, Jalan Pahang, 50586 Kuala Lumpur, Malaysia.
authors.forename: Hiew
authors.initials: H
authors.lastname: Fu Liong
authors.affiliation: Molecular Diagnostics and Protein Unit, Institute for Medical Research (IMR), Jalan Pahang, 50586 Kuala Lumpur, Malaysia.
authors.forename: Siti Aishah
authors.initials: SA
authors.lastname: Abdul Wahab
authors.affiliation: Molecular Diagnostics and Protein Unit, Institute for Medical Research (IMR), Jalan Pahang, 50586 Kuala Lumpur, Malaysia.
authors.forename: Yusnita
authors.initials: Y
authors.lastname: Yakob
authors.affiliation: Department of Genetics, Kuala Lumpur General Hospital, Jalan Pahang, 50586 Kuala Lumpur, Malaysia.
authors.forename: Ngu
authors.initials: N
authors.lastname: Lock Hock
authors.affiliation: Department of Pathology, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur, Malaysia.
authors.forename: Wong Kum
authors.initials: WK
authors.lastname: Thong
authors.affiliation: Department of Neurology, Kuala Lumpur General Hospital, Jalan Pahang, 50586 Kuala Lumpur, Malaysia.
authors.forename: Shanthi
authors.initials: S
authors.lastname: Viswanathan
references.citation: Zhonghua Er Ke Za Zhi. 2007 Oct;45(10):760-4
references.pmid: 18211760
references.citation: J Neurol. 2008 Jun;255(6):831-8
references.pmid: 18458862
references.citation: N Engl J Med. 2010 Apr 15;362(15):1396-406
references.pmid: 20393176
references.citation: Neurology. 2007 Jan 9;68(2):99-109
references.pmid: 17151339
references.citation: Biochem J. 1990 Dec 1;272(2):493-7
references.pmid: 2268276
references.citation: JAMA Neurol. 2013 Jun;70(6):756-63
references.pmid: 23609947
references.citation: Mol Genet Metab. 2011 Nov;104(3):284-8
references.pmid: 21757382
references.citation: Neurology. 1983 Jan;33(1):34-8
references.pmid: 6401355
references.citation: J Neurol. 2010 Jan;257(1):91-7
references.pmid: 19649685
references.citation: Am Rev Respir Dis. 1986 Aug;134(2):328-31
references.pmid: 3090917
references.citation: J Neurol. 2013 Apr;260(4):951-9
references.pmid: 22926164
references.citation: Am J Hum Genet. 1995 Apr;56(4):887-97
references.pmid: 7717400
references.citation: Orphanet J Rare Dis. 2012 Jun 07;7:35
references.pmid: 22676651
references.citation: Brain. 2005 Mar;128(Pt 3):671-7
references.pmid: 15659425
references.citation: Neuromuscul Disord. 2007 Oct;17(9-10):698-706
references.pmid: 17643989
references.citation: Orphanet J Rare Dis. 2013 Mar 27;8:49
references.pmid: 23531252
references.citation: Eur J Pediatr. 1997 Aug;156 Suppl 1:S39-42
references.pmid: 9266214