Polyglucosan Body Disease Research Articles

A Case of Congenital Glycogen Storage Disease Type IV With a Novel GBE1 Mutation

Glycogen storage disease type IV (Andersen disease) is a rare metabolic disorder characterized by deficient glycogen branching enzyme activity resulting in abnormal, amylopectin-like glycogen deposition in multiple organs. This article reports on an infant with the congenital neuromuscular subtype of glycogen storage disease type IV who presented with polyhydramnios, hydrops fetalis, bilateral ankle contractures, biventricular cardiac dysfunction, and severe facial and extremity weakness. A muscle biopsy showed the presence of material with histochemical and ultrastructural characteristics consistent with amylopectin. Biochemical analysis demonstrated severely reduced branching enzyme activity in muscle tissue and fibroblasts. Genetic analysis demonstrated a novel deletion of exon 16 within GBE1, the gene associated with glycogen storage disease type IV. Continued genetic characterization of glycogen storage disease type IV patients may aid in predicting clinical outcomes in these patients and may also help in identifying treatment strategies for this potentially devastating metabolic disorder.

Hepatic disease as the first manifestation of progressive myoclonus epilepsy of Lafora

Lafora disease (LD; progressive myoclonus epilepsy type 2; EPM2) is an autosomal recessive disorder caused by mutations in the EPM2A and EPM2B genes. LD is characterized by the presence of strongly PAS-positive intracellular inclusions (Lafora bodies) in several tissues. Glycogen storage disease type IV (GSD-IV; Andersen disease) is an autosomal recessive disorder characterized by cirrhosis leading to severe liver failure. GSD-IV has been associated with mutations in the glycogen branching enzyme gene (GBE). Histopathologic changes of the liver in both diseases show an identical appearance, although cirrhosis has never been described in patients with LD. We report a LD family in which the proband presented severe liver failure at onset of the disease. Clinical histories, physical and neurologic examination, laboratory tests, EEGs, MRI of the brain, and liver or axillary skin biopsies were performed in the two affected siblings. The diagnosis was confirmed by molecular genetic analysis of the EPM2A, EPM2B, and GBE genes and loci. During the first decade of life, abnormalities in liver function tests were detected in the two affected siblings. The proband's liver dysfunction was severe enough to require liver transplantation. Subsequently, both sibs developed LD. Mutation analysis of EPM2A revealed a homozygous Arg241stop mutation in both patients. This is the first description of severe hepatic dysfunction as the initial clinical manifestation of LD. The phenotypic differences between the two affected siblings suggest that modifier genes must condition clinical expression of the disease outside the CNS.

Identification and Characterization of a New Class of Trafficking Motifs for Controlling Clathrin-independent Internalization and Recycling

Plasma membrane proteins such as receptors and ion channels allow a cell to communicate with its environment and regulate many intracellular activities. Thus, the proper control of the surface number of these proteins is essential for maintaining the structural and functional homeostasis of a cell. Internalization and recycling plays a key role in determining the surface density of receptors and channels. Whereas the clathrin-mediated internalization and its associated recycling have been the focus of research in this field, recent studies have revealed that an increasing number of receptors and channels enter a cell via clathrin-independent pathways. However, little is known about the trafficking motifs involved in controlling clathrin-independent internalization and various associated recycling pathways. By using a potassium channel as a model system, we identified a class of trafficking motifs that function along a clathrin-independent pathway to increase the surface density of a membrane protein by preventing its rapid internalization and/or facilitating its recycling via the ADP-ribosylation factor 6-dependent recycling pathway. Moreover our data suggest that these motifs may enhance the association of membrane proteins with the EFA6 family of guanine nucleotide exchange factors for ADP-ribosylation factor 6.

Polyglucosan body disease myopathy: An unusual presentation

Polyglucosan body disease (PBD) is a slowly progressive adult-onset glycogen storage disorder that typically affects upper and lower neurons. Myopathy, as a complication of PBD has been reported rarely and clinically manifests as chronic limb-girdle muscle weakness. We report an unusual case of PBD myopathy presenting as an asymmetric motor syndrome that clinically overlapped with amyotrophic lateral sclerosis, further expanding the phenotype of this disorder.

A Case of Adult Polyglucosan Body Disease

Adult polyglucosan body disease (APBD) is a rare neurological disease, characterized by adult onset (fifth to seventh decades), progressive sensorimotor or pure motor peripheral neuropathy, upper motor neuron symptoms, neurogenic bladder, and cognitive impairment. APBD is confirmed by a sural nerve biopsy that shows the widespread presence of polyglucosan bodies in the nerve. We report a 70 year old male patient who exhibited progressive weakness in all extremities and dementia. His electrodiagnostic studies showed sensorimotor polyneuropathy and muscle pathology that consisted of polyglucosan bodies located in small peripheral nerves. This is the first case of APBD reported in Korea.

Prenatal diagnosis of glycogen storage disease type IV

Glycogen storage disease type IV (GSD-IV) is a rare autosomal recessive disorder due to mutations in the GBE1 gene causing deficiency of the glycogen branching enzyme (GBE). Prenatal diagnosis has occasionally been performed by the measurement of the GBE activity in cultured chorionic villi (CV) cells. Two unrelated probands with severe hypotonia at birth and death during the neonatal period were diagnosed with GSD-IV on the basis of postmortem histological findings. DNA analysis revealed truncating GBE1 mutations in both families. Prenatal diagnosis was performed in subsequent pregnancies by determination of branching enzyme activity and DNA analysis of CV or cultured amniocytes. Detailed autopsies of the affected fetuses at 14 and 24 weeks of gestation demonstrated intracellular inclusions of abnormal glycogen characteristic of GSD-IV. Prenatal diagnosis of GSD-IV by DNA analysis is highly accurate in genetically confirmed cases.

G.P.1 05 The clinical spectrum of glycogen storage disease type IV (Andersen disease)

Glycogen storage disease type IV (GSD IV, Andersen disease) is a rare metabolic disorder characterized by deficient glycogen branching enzyme activity resulting in abnormal, diastase-resistant glycogen deposition in multiple organs. Although the classic presentation is hepatosplenomegaly with liver cirrhosis in infancy, GSD IV exhibits clinical heterogeneity with respect to age of onset and pattern of organ involvement. We report two patients with confirmed GSD IV on biochemical testing, and a third probable case.

Stable neuropsychological deficits in adult polyglucosan body disease

We describe a 61-year-old woman who gradually developed deficits of balance, gait, and the ability to negotiate movement in space, together with an unusual pattern of cognitive deficits. A series of non-invasive investigations over three years including EEG, CT, MRI, PET and serial neuropsychological review had not provided a diagnosis. Significantly, the four neuropsychological assessments had revealed no progressive decline in cognition. Brain biopsy revealed an abundance of corpora amylacea, and a diagnosis of adult polyglucosan body disease (APBD) was made. This case contributes to the body of knowledge about the cognitive manifestations of this rare disease, and the stability of its functional impact over time.

Non-lethal congenital hypotonia due to glycogen storage disease type IV

Glycogen storage disease type IV (GSD-IV) is an autosomal recessive genetic disorder due to a deficiency in the activity of the glycogen branching enzyme (GBE). A deficiency in GBE activity results in the accumulation of glycogen with fewer branching points and long, unbranched outer chains. The disorder results in a variable phenotype, including musculoskeletal, cardiac, neurological, and hepatic involvement, alone or in continuum, which can be identified at any stage of life. The classic form of GSD-IV is a hepatic presentation, which presents in the first 18 months of life with failure to thrive, hepatomegaly, and cirrhosis that progresses to liver failure, resulting in death by age 5 years. A severe congenital musculoskeletal phenotype with death in the neonatal period has also been described. We report an unusual case of congenital musculoskeletal presentation of GSD-IV with stable congenital hypotonia, gross motor delay, and severe fibro-fatty replacement of the musculature, but no hepatic or cardiac involvement. Molecular analysis revealed two novel missense mutations with amino acid changes in the GBE gene (Q236H and R262C), which may account for the mild phenotype.

Cognitive impairment in neuromuscular disorders

Several studies have suggested the presence of central nervous system involvement manifesting as cognitive impairment in diseases traditionally confined to the peripheral nervous system. The aim of this review is to highlight the character of clinical, genetic, neurofunctional, cognitive, and psychiatric deficits in neuromuscular disorders. A high correlation between cognitive features and cerebral protein expression or function is evident in Duchenne muscular dystrophy, myotonic dystrophy (Steinert disease), and mitochondrial encephalomyopathies; direct correlation between tissue-specific protein expression and cognitive deficits is still elusive in certain neuromuscular disorders presenting with or without a cerebral abnormality, such as congenital muscular dystrophies, congenital myopathies, amyotrophic lateral sclerosis, adult polyglucosan body disease, and limb-girdle muscular dystrophies. No clear cognitive deficits have been found in spinal muscular atrophy and facioscapulohumeral dystrophy.

Adult polyglucosan body disease: A case report of a manifesting heterozygote

A 62-year-old man developed progressive gait instability, bladder dysfunction, proximal weakness, distal sensory loss, and mild cognitive impairment over 6 years. Neurologic examination revealed upper and lower motor neuron dysfunction in the lower extremities, with distal sensory loss. Electrodiagnostic studies, magnetic resonance imaging of the brain, and sural nerve biopsy were consistent with adult polyglucosan body disease. Biochemical and genetic analyses demonstrated reduced glycogen brancher enzyme levels associated with a heterozygous point mutation (Tyr329Ser or Y329S) in the glycogen brancher enzyme gene on chromosome 3. Mutational heterozygosity in the glycogen brancher enzyme gene has not been previously reported as a cause for this rare disease. A review of the clinical presentation, pathogenesis, etiology, and diagnosis of this disease is presented.

Inherited cardiac arrhythmia syndromes: What have they taught us about arrhythmias and anti‐arrhythmic therapy?

1. In recent years, the identification of the gene defects in a vast array of monogenic disorders has revolutionized our understanding of the basic mechanisms underlying numerous disease processes. 2. Mutations in cardiac ion channels have been identified as the basis of a wide range of inherited arrhythmia syndromes, including the congenital long QT syndromes, Brugada syndrome, Lenegre syndrome, Andersen's disease and familial atrial fibrillation. 3. Identification of mutations in the human-ether-a-go-go-related gene (HERG) K(+) channel as the molecular basis of congenital long QT syndrome type 2 also led to the discovery that HERG is the molecular target for the vast majority of drugs (both cardiac and non-cardiac) that cause drug-induced arrhythmias. This has had profound implications not only for the development of anti-arrhythmic agents, but also for drug development in general. 4. The sequencing of the human genome in a sense represents the pinnacle of the reductionist era of molecular medicine. The great challenge now is to re-integrate the information gathered during the 'reductionist era' to provide a better understanding of the intact organism. Computer modelling is likely to be a key component of that re-integration process.

Fatal infantile neuromuscular presentation of glycogen storage disease type IV

Glycogen storage disease type IV or Andersen disease is an autosomal recessive disorder due to deficiency of glycogen branching enzyme. Typically, glycogen storage disease type IV presents with rapidly progressive liver cirrhosis and death in childhood. Variants include a cardiopathic form of childhood, a relatively benign myopathic form of young adults, and a late-onset neurodegenerative disorder (adult polyglucosan body disease). A severe neuromuscular variant resembling Werdnig-Hoffmann disease has also been described in two patients. The objective was to describe two additional infants with the neuromuscular variant and novel mutations in the GBE1 gene. Branching enzyme assay, Western blot, RT-PCR and sequencing were performed in muscle biopsies from both patients. The cDNA of patient 1 was subcloned and sequenced to define the mutations. Muscle biopsies showed accumulation of periodic acid Schiff-positive, diastase-resistant storage material in both patients and increased lysosomal enzyme activity in patient 1. Branching enzyme activity in muscle was negligible in both patients, and Western blot showed decreased branching enzyme protein. Patient 1 had two single base pair deletions, one in exon 10 (1238delT) and the other in exon 12 (1467delC), and each parent was heterozygous for one of the deletions. Patient 2 had a large homozygous deletion that spanned 627 bp and included exons 8–12. Patient 1, who died at 41 days, had neurophysiological and neuropathological features of Spinal Muscular Atrophy. Patient 2, who died at 5 1 2 weeks, had a predominantly myopathic process. The infantile neuromuscular form of glycogen storage disease type IV is considered extremely rare, but our encountering two patients in close succession suggests that the disease may be underdiagnosed.

Adult polyglucosan body disease: Case description of an expanding genetic and clinical syndrome

A non-Jewish patient is described who had adult polyglucosan body disease (APBD) and glycogen branching enzyme (GBE) deficiency without GBE mutation. A heterozygous polymorphism (Val160Ile) was found, and also discovered in 1 of 50 normal individuals. Magnetic resonance imaging demonstrated increased T2 signal in the midbrain, medullary olives, dentate nuclei, cerebellar peduncles, and internal and external capsules, with vermian atrophy. Both muscle and nerve biopsy revealed perivascular inflammatory infiltrates. These findings expand the clinical and genetic spectrum of APBD. Factors other than mutation of the expressed GBE gene may cause enzyme deficiency and varied expression and development of APBD.

Andersen mutations of KCNJ2 suppress the native inward rectifier current in a dominant-negative fashion

The Andersen's syndrome is a hereditary disease, which is characterized by cardiac arrhythmias, periodic paralysis and dysmorphic features. Recently, mutations of the KCNJ2 gene, which encodes the inward rectifying potassium channel subunit Kir2.1, have been identified in affected individuals. However, the functional effects of these mutations have not yet been fully elucidated. To clarify this situation we generated known Andersen disease mutants of KCNJ2 which did not yield any measurable K(+) currents in CHO cells indicating that the Andersen mutants failed to form functional homomultimeric complexes. EGFP-tagged KCNJ2 wild-type and mutant channels distributed in a similar homogeneous pattern in the cell membrane suggesting that protein trafficking was not altered by the Andersen mutations but rather implicating that the mutations rendered the KCNJ2 channel non-functional. In heterologous coexpression experiments the Andersen mutants exerted a dominant-negative effect on wild-type KCNJ2. However, the extent of suppression varied between the different KCNJ2 mutants. Given our results in CHO cells, we expressed the disease mutant KCNJ2-S136F in neonate rat cardiomyocytes using adenoviral gene transfer to test the effect of Andersen mutants on native I(K1). I(K1) density was indeed significantly reduced in KCNJ2-S136F-infected cells (n=9) compared to control cells (n=9) over a voltage range from -70 to -150 mV (P<0.05). These results support that Kir2.x channels are a critical component of native I(K1) in neonate rat cardiomyocytes and that a dominant-negative suppression of I(K1) in native cells is the pathophysiological correlate of the Andersen's syndrome.

Type IV Glycogen Storage Disease

A male infant presented with massive hepatomegaly. There was no history of jaundice, fever, weight loss, blood in stool, or acholic stool. He was born at full term without any complications, and the newborn screening test results were normal. The maternal perinatal history was unremarkable for infections, previous blood transfusion, or intravenous drug use. Family history was negative for jaundice, early infantile death, neurodegenerative disorder, or a1-antitrypsin deficiency. Physical examination revealed normal growth and vital signs, no icterus, lymphadenopathy, ascites, splenomegaly, or other systemic abnormal findings. Firm, nontender hepatomegaly was noted 8 cm below the right costal margin. Laboratory results included a total bilirubin level of 0.5 mg/ dL (9 mmol/L); aspartate aminotransferase, 956 U/L (reference range, 0–50 U/L); alanine aminotransferase, 287 U/L (reference range, 0–45U/L); g-glutamyltransferase, 216 U/L (reference range, 5–32 U/L); and alkaline phosphatase, 321 U/L (reference range, 170–580 U/L). Urine was negative for reducing substances. Results for complete blood count, prothrombin time, partial thromboplastin time, total protein, albumin, serum ferritin, cholesterol, and lactate dehydrogenase were all within normal limits. The hepatitis antibody panel (hepatitis B and C, cytomegalovirus, and Epstein-Barr virus) was negative. A percutaneous needle biopsy of the liver showed loss of normal hepatic architecture, bridging fibrosis, and micronodule formation that was confirmed by trichrome stain. Many scattered hepatocytes showed glassy refractile cytoplasmic inclusions (Figure, A), which stained positively with periodic acid–Schiff (Figure, B) and were generally sensitive to diastase digestion. These inclusions appeared light blue with Alcian blue stain and showed coarsely clumped staining with colloidal iron stain (Figure, C). An ultrastructural evaluation of formalin-fixed tissue showed hepatocytes filled with rarefied fibrillar material interspersed with microfoci of normal glycogen (Figure, D). A diagnosis of glycogen storage disease, type IV, was rendered. Type IV glycogen storage disease (type IV GSD), also known as Andersen disease or amylopectinosis, is a rare autosomal-recessive disorder caused by the deficiency of

The variable presentations of glycogen storage disease type IV: a review of clinical, enzymatic and molecular studies.

Glycogen storage disease type IV (GSD-IV), also known as Andersen disease or amylopectinosis (MIM 23250), is a rare autosomal recessive disorder caused by a deficiency of glycogen branching enzyme (GBE) leading to the accumulation of amylopectin-like structures in affected tissues. The disease is extremely heterogeneous in terms of tissue involvement, age of onset and clinical manifestations. The human GBE cDNA is approximately 3-kb in length and encodes a 702-amino acid protein. The GBE amino acid sequence shows a high degree of conservation throughout species. The human GBE gene is located on chromosome 3p14 and consists of 16 exons spanning at least 118 kb of chromosomal DNA. Clinically the classic Andersen disease is a rapidly progressive disorder leading to terminal liver failure unless liver transplantation is performed. Several mutations have been reported in the GBE gene in patients with classic phenotype. Mutations in the GBE gene have also been identified in patients with the milder non-progressive hepatic form of the disease. Several other variants of GSD-IV have been reported: a variant with multi-system involvement including skeletal and cardiac muscle, nerve and liver; a juvenile polysaccharidosis with multi-system involvement but normal GBE activity; and the fatal neonatal neuromuscular form associated with a splice site mutation in the GBE gene. Other presentations include cardiomyopathy, arthrogryposis and even hydrops fetalis. Polyglucosan body disease, characterized by widespread upper and lower motor neuron lesions, can present with or without GBE deficiency indicating that different biochemical defects could result in an identical phenotype. It is evident that this disease exists in multiple forms with enzymatic and molecular heterogeneity unparalleled in the other types of glycogen storage diseases.

Polyglucosan body disease in a mixed-breed dog

AIM: To describe the histopathology of a previously unrecorded canine disease and deduce the cause of the lesions. METHODS: Formalin-fixed tissues were processed into paraffin wax and epoxy resin for light and electron microscopy of variously stained sections of liver, brain, heart muscle and kidney. RESULTS: Periodic acid Schiff (PAS) -positive bodies in liver and myocardium were typical of a polyglucosan body disease. Neurons contained coarse granular material that stained similarly to the polyglucosan bodies. CONCLUSION: The nature, distribution and histochemistry of lesions observed are consistent with a putative diagnosis of Glycogen storage disease type IV, an inherited metabolic defect associated with a deficiency of glycogen-branching enzyme not previously reported in dogs.

Surprises of genetic engineering: a possible model of polyglucosan body disease.

The authors previously reported the generation of a knockout mouse model of Pompe disease caused by the inherited deficiency of lysosomal acid alpha-glucosidase (GAA). The disorder in the knockout mice (GAA-/-) resembles the human disease closely, except that the clinical symptoms develop late relative to the lifespan of the animals. In an attempt to accelerate the course of the disease in the knockouts, the authors increased the level of cytoplasmic glycogen by overexpressing glycogen synthase (GSase) or GlutI glucose transporter. GAA-/- mice were crossed to transgenic mice overexpressing GSase or GlutI in skeletal muscle. Both transgenics on a GAA knockout background (GS/GAA-/- and GlutI/GAA-/-) developed a severe muscle wasting disorder with an early age at onset. This finding, however, is not the major focus of the study. Unexpectedly, the mice bearing the GSase transgene, but not those bearing the GlutI transgene, accumulated structurally abnormal polysaccharide (polyglucosan) similar to that observed in patients with Lafora disease, glycogenosis type IV, and glycogenosis type VII. Ultrastructurally, the periodic acid-Schiff (PAS)-positive polysaccharide inclusions were composed of short, amorphous, irregular branching filaments indistinguishable from classic polyglucosan bodies. The authors show here that increased level of GSase in the presence of normal glycogen branching enzyme (GBE) activity leads to polyglucosan accumulation. The authors have further shown that inactivation of lysosomal acid alpha-glucosidase in the knockout mice does not contribute to the process of polyglucosan formation. An imbalance between GSase and GBE activities is proposed as the mechanism involved in the production of polyglucosan bodies. The authors may have inadvertently created a "muscle polyglucosan disease" by simulating the mechanism for polyglucosan formation.

Probable Adult Polyglucosan Body Disease

Adult polyglucosan body disease is a clinicopathologic entity characterized by progressive upper and lower motor neuron dysfunction, sensory loss in the lower extremities, sphincter dysfunction, and occasionally dementia. Pathologically, numerous large polyglucosan bodies are noted in peripheral nerves, cerebral hemispheres, and the spinal cord, as well as in other systemic tissues. We present a case of probable adult polyglucosan body disease based on clinical history and examination, magnetic resonance images, and sural nerve biopsy findings.