Generation of three induced pluripotent stem cell lines from patients with glycogen storage disease type III

Glycogen storage disease type III (GSDIII) is an autosomal recessive disorder characterized by a deficiency of glycogen debranching enzyme (GDE) leading to cytosolic glycogen accumulation and inducing liver and muscle pathology. Skin fibroblasts from three GSDIII patients were reprogrammed into induced pluripotent stem cells (iPSCs) using non-integrated Sendai virus. All of the three lines exhibited normal morphology, expression of pluripotent markers, stable karyotype, potential of trilineage differentiation and absence of GDE expression, making them valuable tools for modeling GSDIII disease in vitro, studying pathological mechanisms and investigating potential treatments.

Natural Progression of Canine Glycogen Storage Disease Type IIIa

Glycogen storage disease type IIIa (GSD IIIa) is caused by a deficiency of glycogen debranching enzyme activity. Hepatomegaly, muscle degeneration, and hypoglycemia occur in human patients at an early age. Long-term complications include liver cirrhosis, hepatic adenomas, and generalized myopathy. A naturally occurring canine model of GSD IIIa that mimics the human disease has been described, with progressive liver disease and skeletal muscle damage likely due to excess glycogen deposition. In the current study, long-term follow-up of previously described GSD IIIa dogs until 32 mo of age (n = 4) and of family-owned GSD IIIa dogs until 11 to 12 y of age (n = 2) revealed that elevated concentrations of liver and muscle enzyme (AST, ALT, ALP, and creatine phosphokinase) decreased over time, consistent with hepatic cirrhosis and muscle fibrosis. Glycogen deposition in many skeletal muscles; the tongue, diaphragm, and heart; and the phrenic and sciatic nerves occurred also. Furthermore, the urinary biomarker Glc4, which has been described in many types of GSD, was first elevated and then decreased later in life. This urinary biomarker demonstrated a similar trend as AST and ALT in GSD IIIa dogs, indicating that Glc4 might be a less invasive biomarker of hepatocellular disease. Finally, the current study further demonstrates that the canine GSD IIIa model adheres to the clinical course in human patients with this disorder and is an appropriate model for developing novel therapies.

Mouse model of glycogen storage disease type III

Glycogen storage disease type IIIa (GSD IIIa) is caused by a deficiency of the glycogen debranching enzyme (GDE), which is encoded by the Agl gene. GDE deficiency leads to the pathogenic accumulation of phosphorylase limit dextrin (PLD), an abnormal glycogen, in the liver, heart, and skeletal muscle. To further investigate the pathological mechanisms behind this disease and develop novel therapies to treat this disease, we generated a GDE-deficient mouse model by removing exons after exon 5 in the Agl gene. GDE reduction was confirmed by western blot and enzymatic activity assay. Histology revealed massive glycogen accumulation in the liver, muscle, and heart of the homozygous affected mice. Interestingly, we did not find any differences in the general appearance, growth rate, and life span between the wild-type, heterozygous, and homozygous affected mice with ad libitum feeding, except reduced motor activity after 50 weeks of age, and muscle weakness in both the forelimb and hind legs of homozygous affected mice by using the grip strength test at 62 weeks of age. However, repeated fasting resulted in decreased survival of the knockout mice. Hepatomegaly and progressive liver fibrosis were also found in the homozygous affected mice. Blood chemistry revealed that alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) activities were significantly higher in the homozygous affected mice than in both wild-type and heterozygous mice and the activity of these enzymes further increased with fasting. Creatine phosphokinase (CPK) activity was normal in young and adult homozygous affected mice. However, the activity was significantly elevated after fasting. Hypoglycemia appeared only at a young age (3 weeks) and hyperlipidemia was not observed in our model. In conclusion, with the exception of normal lipidemia, these mice recapitulate human GSD IIIa; moreover, we found that repeated fasting was detrimental to these mice. This mouse model will be useful for future investigation regarding the pathophysiology and treatment strategy of human GSD III.

Bulbar muscle weakness and fatty lingual infiltration in glycogen storage disorder type IIIa

Glycogen storage disorder type III (GSD III) is a rare autosomal recessive disorder resulting from a deficiency of glycogen debranching enzyme, critical in cytosolic glycogen degradation. GSD IIIa, the most common form of GSD III, primarily affects the liver, cardiac muscle, and skeletal muscle. Although skeletal muscle weakness occurs commonly in GSD IIIa, bulbar muscle involvement has not been previously reported. Here we present three GSD IIIa patients with clinical evidence of bulbar weakness based on instrumental assessment of lingual strength. Dysarthria and/or dysphagia, generally mild in severity, were evident in all three individuals. One patient also underwent correlative magnetic resonance imaging (MRI) which was remarkable for fatty infiltration at the base of the intrinsic tongue musculature, as well as abnormal expansion of the fibro-fatty lingual septum. Additionally, we provide supportive evidence of diffuse glycogen infiltration of the tongue at necropsy in a naturally occurring canine model of GSD IIIa. While further investigation in a larger group of patients with GSD III is needed to determine the incidence of bulbar muscle involvement in this condition and whether it occurs in GSD IIIb, clinical surveillance of lingual strength is recommended.

[Diagnosis of glycogen storage disease type IIIA by detecting glycogen debranching enzyme activity, glycogen content and structure in muscle]

OBJECTIVE

Glycogen storage disease type III (GSD III) is an autosomal recessive disease caused by glycogen debranching enzyme (GDE) gene (AGL gene) mutation resulting in hepatomegaly, hypoglycemia, short stature and hyperlipidemia. GSD IIIA, involves both liver and muscle, and accounts for up to 80% of GSD III. The definitive diagnosis depends on either mutation analysis or liver and muscle glycogen debranching enzyme activity tests. This study aimed to establish enzymologic diagnostic method for GSD IIIA firstly in China by detecting muscular GDE activity, glycogen content and structure and to determine the normal range of muscular GDE activity, glycogen content and structure in Chinese children.

METHOD

Muscle samples were collected from normal controls (male 15, female 20; 12-78 years old), molecularly confirmed GSD III A patients (male 8, female 4, 2-27 years old) and other myopathy patients (male 9, 2-19 years old). Glycogen in the muscle homogenate was degraded into glucose by amyloglucosidase and phosphorylase respectively. The glycogen content and structure were identified by glucose yield determination. The debranching enzyme activity was determined using limit dextrin as substrate. Independent samples Kruskal-Wallis H test, Nemenyi-Wilcoxson-Wilcox test, and Chi-square test were used for statistical analyses by SPSS 11.5.

RESULT

(1) GSD III A patients' glycogen content were higher, but G1P/G ratio and GDE activity were lower than those of the other two groups (P < 0.01). In all of the three parameters, there were no significant difference between normal controls and other myopathy patients. (2) The range of normal values: glycogen content 0.31%-0.43%, G1P/G ratio 22.37%- 26.43%, GDE activity 0.234-0.284 micromol/(g. min). (3) Enzymologic diagnostic method had a power similar to that of gene analysis in diagnosis of GSD-IIIA patients. The sensitivity and specificity of enzymologic diagnostic method and mutation detection were 91.7% and 100% respectively.

CONCLUSION

Enzymologic diagnostic method of GSD IIIA was firstly established in China. The range of normal values was determined. This method could be used in diagnosing suspected GSD IIIA patients in the clinic.

[Clinical and pathological features of glycogen storage disease type III]

OBJECTIVES

To summarize the clinical and pathological features of glycogen storage disease (GSD) type III.

METHODS

The clinical data of 12 GSD type III, 8 males and 4 females, aged 2 - 27, were collected. The biopsy specimens of quadriceps muscle of thigh underwent HE and histochemical staining and light and electron microscopy.

RESULTS

The main clinical feature were hepatomegaly and hypoglycemic symptoms, slow growth, and microsome since childhood, while myopathy was mild. Laboratory findings included low plasma glucose (n = 12), high liver transaminases (n = 12), increased CK (n = 11), mild metabolic acidosis (n = 11), hyperlipemia (n = 9), elevation of blood lactate (n = 5), high uric acid (n = 1), and decrease of serum carnitine level (n = 1). One patient had echographic evidence of cardiomyopathy. 11 patients were postprandial adrenalin stimulation test positive. Raw corn starch therapy was used on all patients and showed effective on liver manifestations. Muscle biopsy showed vacuolar myopathy, PAS positive glycogen granules in muscle fibers, small foci of intense ACP reactivity, and deposit of lipid droplets.

CONCLUSION

GSD type III exhibits a clinical heterogeneity. Besides hepatic symptoms, myopathy and cardiomyopathy should be addressed adequately. The degree of pathological change of muscles is not significantly related to the degree of functional impairment, duration of disease, and level of CK.

Glycogen storage disease type IIIa in curly-coated retrievers

BACKGROUND

Inborn errors of metabolism impose a significant genetic burden on purebred dogs and cats. The glycogen storage diseases are a category of such disorders that are typed by enzyme analysis, but deoxyribonucleic acid (DNA) based carrier tests are needed for definitive, noninvasive diagnosis and to prevent at-risk matings.

HYPOTHESIS

Glycogen storage disease type IIIa (GSD IIIa) is caused by a mutation of the glycogen debranching enzyme gene (AGL) in Curly-Coated Retrievers (CCR).

ANIMALS

Two CCR exhibiting episodic exercise intolerance, collapse, and lethargy, and related dogs were studied.

METHODS

Structure and amount of glycogen isolated from tissue biopsy specimens was determined by enzymatic digestion, and activities of enzymes of glycogen metabolism were measured. The 33 AGL coding exons and flanking splice sites of an affected dog were amplified by polymerase chain reaction and sequenced.

RESULTS

Debranching enzyme activity was undetectable in liver and skeletal muscle of affected dogs, and accumulated glycogen had absent or short outer chains of alpha1, 4-linked glucose. A single adenosine (A) deletion in AGL exon 32 of affected dog genomic DNA predicted a frame-shift and truncation of the protein product by 126 amino acid residues. The mutation was homozygous in affected dogs and heterozygous in both parents. In addition, the deletion mutation was heterozygous in 16 or not detected at all in 31 related but clinically normal CCR.

CONCLUSIONS AND CLINICAL IMPORTANCE

GSD IIIa in CCR is an autosomal recessive trait caused by mutation of AGL. A DNA sequence-based carrier test was developed, and carriers were identified in the United States, New Zealand, Australia, and Finland.

Prediction of premature atherosclerosis by endothelial dysfunction and increased intima-media thickness in glycogen storage disease types Ia and III

The aim of this study was to investigate the endothelial dysfunction (ED) and carotid intima-media thickness (IMT) in patients with glycogen storage disease (GSD) types Ia and III. In 22 patients with GSD (13, type Ia; 9, type III) and 18 healthy subjects, endothelial functions of the brachial artery and carotid IMT were evaluated by high-resolution ultrasound. Endothelial-dependent dilatation (EDD) was assessed by establishing reactive hyperemia. EDD and carotid IMTs were compared between the three groups. Mean cholesterol level was slightly higher in GSD type III patients but the difference was not significant. Triglyceride levels and cholesterol to high density lipoprotein (HDL) ratio were significantly higher in GSD type Ia patients. EDD was significantly impaired in GSD type Ia (13% +/- 8%, P = .001) and type III (15% +/- 6%, P = .005) patients when compared with the healthy subjects (22% +/- 4%). The carotid IMT was significantly higher in both GSD type Ia (0.23 +/- 0.03 mm, P =.005) and type III (0.26 +/- 0.05 mm, P = .001) patients when compared with the healthy subjects (0.20 +/- 0.02 mm). Both GSD type Ia and type III patients show significant ED and increased IMT, which are predictors of atherosclerosis.

Glycogen storage disease type III-hepatocellular carcinoma a long-term complication?

BACKGROUND/AIMS

Glycogen storage disease III (GSD III) is caused by a deficiency of glycogen-debranching enzyme which causes an incomplete glycogenolysis resulting in glycogen accumulation with abnormal structure (short outer chains resembling limit dextrin) in liver and muscle. Hepatic involvement is considered mild, self-limiting and improves with age. With increased survival, a few cases of liver cirrhosis and hepatocellular carcinoma (HCC) have been reported.

METHODS

A systematic review of 45 cases of GSD III at our center (20 months to 67 years of age) was reviewed for HCC, 2 patients were identified. A literature review of HCC in GSD III was performed and findings compared to our patients.

CONCLUSIONS

GSD III patients are at risk for developing HCC. Cirrhosis was present in all cases and appears to be responsible for HCC transformation There are no reliable biomarkers to monitor for HCC in GSD III. Systematic evaluation of liver disease needs be continued in all patients, despite lack of symptoms. Development of guidelines to allow for systematic review and microarray studies are needed to better delineate the etiology of the hepatocellular carcinoma in patients with GSD III.

Spätmanifestation einer Polyglykosankörpermyopathie

We report two patients with polyglycosan body disease manifesting in adulthood. Clinical, electrophysiological, and histopathological characteristics of their disorders are summarized, and diagnostic classification is discussed.

Polymicrogyria in glycogenosis type III: an incidental finding?

The purpose of the present report is to document a 20-year-old woman with glycogenosis type III who presented a malformation of cortical development, in this case a polymicrogyria over bilateral perisylvian regions. Association of a malformation of cortical development in this type of glycogenosis has not been previously reported. The existence of previous cases of glycogenosis associated with malformations of cortical development led us to believe that glycogen storage during pregnancy may act as a harmful prenatal event. On the other hand, the presence of a lesion associated with severe neurologic deficits in one patient with a milder form of glycogenosis is in disagreement with the idea that there is a strong correlation between the severity of the central nervous system lesion and that of the disease.

Hepatocellular failure in glycogen storage disorder type 3

A case of a 21 years male patient with type 3 glycogen storage disorder diagnosed at necropsy, who died suddenly with hypovolemic shock following a massive upper gastrointestinal bleeding due to hepatocellular failure is reported. Salient features of GSD type 3 are briefly discussed.

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.

A simple, rapid test for the differential diagnosis of glycogen storage disease type 3

BACKGROUND

Type 3 glycogen storage disease is an inborn error of metabolism in young infants that often requires extensive workup. However, this disease manifests with few symptoms other than hepatosplenomegaly. At adolescence, this disease may cause myopathy and cardiomyopathy. Since a significant portion of referrals to pediatrics is for evaluation of a hepatosplenomegaly, the differential diagnosis of this disease assumes importance.

METHODS

The clinical and biochemical findings in 26 patients with the type 3 glycogen storage disease were investigated. Biochemical parameters included ALT, AST, total CK and CK-MB.

RESULTS

Changes in ALT, AST and total CK were observed to varying degrees. However, CK was found to be a diagnostic indicator for type 3 glycogen storage disease and appears to be a pathognomic marker.

CONCLUSIONS

Use of CK may reduce the need for extensive diagnostic profiles and aid in the rapid identification and initiation of management for patients presenting with hepatosplenomegaly.

Perioperative management of a child with glycogen storage disease type III undergoing cardiopulmonary bypass and repair of an atrial septal defect

The glycogen storage diseases (GSD) are a heterogenous group of inherited disorders involving one of the several steps of glycogen synthesis or degradation. Type III GSD, also known as Cori's or Forbe's disease, results from a deficiency of the enzyme, amylo-1,6-glucosidase, which is responsible for the breakdown or debranching of the glycogen molecule during catabolism. As a result of this deficiency, inadequate glycogen breakdown occurs, resulting in hypoglycaemia during periods of fasting or stress, as well as storage of excessive glycogen, predominantly in the liver. Glycogen accumulation in the liver leads to hepatogmegaly and, in some instances, hepatic dysfunction with cirrhosis in the third and fourth decades of life. Additionally, deficiency of the enzyme in skeletal and cardiac muscle can lead to skeletal muscle weakness and cardiomyopathy. We present a 28-month-old girl who presented for anaesthetic care for cardiopulmonary bypass and closure of an atrial septal defect. The potential perioperative implications of GSD type III are discussed.

Clinical and genetic variability of glycogen storage disease type IIIa: seven novel AGL gene mutations in the Mediterranean area

Deficiency of amylo-1,6-glucosidase, 4-alpha-glucanotransferase enzyme (AGL or glycogen debrancher enzyme) is responsible for glycogen storage disease type III, a rare autosomal recessive disorder of glycogen metabolism. The AGL gene is located on chromosome 1p21, and contains 35 exons translated in a monomeric protein product. The disease has recognized clinical and biochemical heterogeneity, reflecting the genotype-phenotype heterogeneity among different subjects. The clinical manifestations of GSD III are represented by hepatomegaly, hypoglycemia, hyperlipidemia, short stature and, in a number of subjects, cardiomyopathy and myopathy. In this article, we discuss the genotypic-phenotypic heterogeneity of GSD III by the molecular characterization of mutations responsible for the disease on a collection of 18 independent alleles from the Mediterranean area. We identified by heteroduplex band shift, DNA direct sequencing, and restriction analysis, seven novel mutations (four nonsense point-mutations: R34X, S530X, R1218X, W1398X; two microinsertions: 1072insT and 4724insAA; and one bp deletion: 676DeltaG), together with two new cases carrying a IVS21 + 1 G --> A splicing site mutation previously described in Italian patients. Altogether, 15 alleles were characterized. The correlation between type of mutation and clinical severity was studied in six patients in whom both mutated alleles were detected. Our data confirm the extreme genetic heterogeneity of this disease, thus precluding a strategy of mutation finding based on screening of recurrent common mutations.

Facial appearance in glycogen storage disease type III

Amylo-1,6-glucosidase deficiency (glycogen storage disease type III) is associated with hypoglycaemia, hepatomegaly, raised transaminases and in most cases skeletal myopathy and cardiomyopathy. The disorder has not been considered to cause dysmorphism. We report consistent facial features in seven patients with GSD type III consisting of midface hypoplasia with a depressed nasal bridge and a broad upturned nasal tip, indistinct philtral pillars, and bow-shaped lips with a thin vermillon border. Younger patients had in addition deepset eyes. Several children had clinical problems such as persistent otitis media or recurrent sinusitis. The underlying aetiology of these features is unknown but the similarity in all our patient suggests that there is a facial phenotype for this disorder.

Glycogen branching enzyme deficiency in quarter horse foals

Seven related Quarter Horse foals that died by 7 weeks of age were examined for glycogen branching enzyme (GBE) deficiency. Clinical signs varied from stillbirth, transient flexural limb deformities, seizures, and respiratory or cardiac failure to persistent recumbency. Leukopenia (5 of 5 foals) as well as high serum creatine kinase (CK; 5 of 5), aspartate transaminase (AST; 4 of 4), and gamma glutamyl transferase (GGT; 5 of 5) activities were present in most foals, and intermittent hypoglycemia was present in 2 foals. Gross postmortem lesions were minor, except for pulmonary edema in 2 foals. Muscle, heart, or liver samples from the foals contained abnormal periodic acid Schiff's (PAS)-positive globular or crystalline intracellular inclusions in amounts proportional to the foal's age at death. Accumulation of an unbranched polysaccharide in tissues was suggested by a shift in the iodine absorption spectra of polysaccharide isolated from the liver and muscle of affected foals. Skeletal muscle total polysaccharide concentrations were reduced by 30%, but liver and cardiac muscle glycogen concentrations were normal. Several glycolytic enzyme activities were normal, whereas GBE activity was virtually absent in cardiac and skeletal muscle, as well as in liver and peripheral blood cells of affected foals. GBE activities in peripheral blood cells of dams of affected foals and several of their half-siblings or full siblings were approximately 50% of controls. GBE protein in liver determined by Western blot was markedly reduced to absent in affected foals, and in a half-sibling of an affected foal, it was approximately one-half the amount of normal controls. Pedigree analysis also supported an autosomal recessive mode of inheritance. The affected foals have at least 2,600 half-siblings. Consequently, GBE deficiency may be a common cause of neonatal mortality in Quarter Horses that is obscured by the variety of clinical signs that resemble other equine neonatal diseases.

Novel exon 11 skipping mutation in a patient with glycogen storage disease type IIId

We report the molecular genetic abnormalities of a patient with GSD IIId presenting with progressive myopathy and cardiopathy leading to a fatal outcome. We identified two independent deletions including a 4 bp deletion (117-1120) and a 98 bp deletion (1135-1232) in cDNA. Sequencing of the genomic DNA of the corresponding region revealed a 4 bp deletion in exon 10; however, the other 98 bp deletion corresponding to exon 11, which was deleted in cDNA, was present in genomic DNA. We therefore concluded that skipping of exon 11 occurred in the cDNA of the patient. Intron/exon boundary analysis of the skipped exon 11 revealed no mutation in the consensus splice-site sequence. If normal splicing had occurred, a stop codon would have appeared within exon II due to frameshift mutation. The mechanism of exon skipping observed in our patient is as yet unknown, and it is still not clear whether intraexonal mutation of the preceding exon can influence splice-site selection. It is possible that a unique exon skipping occurred, preventing the appearance of a stop codon in our patient.

Hepatocellular carcinoma complicating liver cirrhosis in type IIIa glycogen storage disease

Type III glycogen storage disease (GSD III) is an autosomal recessive disorder characterized by the accumulation of abnormal glycogen in the liver and, in most patients, in the muscle. Although liver fibrosis is a well-known consequence of GSD III, until now only eight cases of liver cirrhosis and two cases of hepatocellular carcinoma have been described in patients affected by this disease. In this case report, the authors describe the clinical history of a patient affected by GSD III who developed severe liver disease during her adult life, progressing from fibrosis to cirrhosis and finally to hepatocellular carcinoma. Until now, the hepatic involvement in GSD III has been considered by most authors as mild and almost always self-limiting. This report, together with the previously published cases, clearly indicates that severe and progressive liver disease may complicate this metabolic disorder. These observations advise a careful hepatologic follow-up of patients affected by GSD III.

Novel mutations in two Japanese cases of glycogen storage disease type IIIa and a review of the literature of the molecular basis of glycogen storage disease type III

We report two novel mutations in two Japanese patients with glycogen storage disease type IIIa (GSD IIIa). In addition, we review the literature on mutations in GSD III to understand better the molecular basis of GSD III. In our first case, the homozygous A-to-C mutation at the acceptor site of intron 5 (IVS5-2A > C) was identified. This leads to the skipping of exon 6 and the predicted mutant protein was found to be 68 amino acids shorter than normal. This is the first report of skipping exon 6, which encodes one of the putative active sites, resulting in a profoundly deleterious effect on debrancher activity. In our second case, the homozygous deletion of an A at position 4234 (4234delA) was identified; this induces a frameshift resulting in the appearance of a stop codon at amino acid position 1276 (1276X). In patients with GSD IIIa, several mutations of the debrancher gene located in the C-terminal region containing putative glycogen binding domains have been identified as well as 4234delA in our second case. On the other hand, specific localization of the mutations within exon 3 was proposed in patients with GSD IIIb.

Reversible severe myopathy of respiratory muscles due to adult-onset type III glycogenosis

Subacute severe myopathy of the respiratory muscles developed in a 47-year-old woman after a 3-week period of strict fasting. Histological and biochemical work-up of muscle biopsy specimens permitted the diagnosis of debrancher deficiency. The course of the disease was characterized by subacute respiratory failure and prolonged mechanical ventilation. After initiation of a high-protein diet the patient was successfully weaned from the respirator and recovered well. To our knowledge this is the first reported case of adult-onset debrancher deficiency myopathy presenting with subacute respiratory failure and responding to high-protein diet.

Different clinical aspects of debrancher deficiency myopathy

OBJECTIVE

To characterise the main clinical phenotypes of debrancher deficiency myopathy and to increase awareness for this probably underdiagnosed disorder.

METHODS

The diagnosis of debrancher deficiency was established by laboratory tests, EMG, and muscle and liver biopsy.

RESULTS

Four patients with debrancher deficiency myopathy were identified in the Tyrol, a federal state of Austria with half a million inhabitants. Clinical appearance was highly variable. The following phenotypes were differentiated: (1) adult onset distal myopathy; (2) subacute myopathy of the respiratory muscles; (3) severe generalised myopathy; and (4) minimal variant myopathy. Exercise intolerance was uncommon. The clinical course was complicated by advanced liver dysfunction in two patients and by severe cardiomyopathy in one. All had raised creatine kinase concentrations (263 to 810 U/l), myogenic and neurogenic features on EMG, and markedly decreased debrancher enzyme activities in muscle or liver biopsy specimens. The findings were substantiated by a review of 79 previously published cases with neuromuscular debrancher deficiency.

CONCLUSIONS

This study illustrates the heterogeneity of neuromuscular manifestations in debrancher deficiency. Based on the clinical appearance, age at onset, and course of disease four phenotypes may be defined which differ in prognosis, frequency of complications, and response to therapy.

Fatal liver cirrhosis and esophageal variceal hemorrhage in a patient with type IIIa glycogen storage disease

A 45-year-old woman with type IIIa glycogen storage disease (GSD IIIa) died of variceal hemorrhage secondary to liver cirrhosis. The postmortem examination disclosed increased intracellular glycogen in the liver as well as in the heart and skeletal muscle. Although most liver injuries in GSD IIIa have been considered to be non-progressive in adulthood, liver cirrhosis can be a cause of death in some patients.

Case report: rupture of a gastric varix in liver cirrhosis associated with glycogen storage disease type III

Glycogen storage disease type III, or Cori's disease, is caused by a deficiency of amylo-1,6-glucosidase (debranching enzyme), which leads to the storage of an abnormal glycogen in the liver and in skeletal and heart muscle. Glycogen storage disease type III is usually characterized by hepatic symptoms, growth failure and myopathy. Even though liver cirrhosis is reported, portal hypertension is a rare complication of this disease. We describe the case of a glycogen storage disease type III patient who was diagnosed at 3 years of age and developed complications (liver cirrhosis and rupture of a gastric varix) at 31 years of age. We discuss the histological progression to cirrhosis of the liver and describe the liver enzyme profile at 3 and 31 years of age.

Type IIIb glycogen storage disease associated with end-stage cirrhosis and hepatocellular carcinoma. The Liver Transplant Group

Type III glycogen storage disease (GSD) is a disorder of carbohydrate metabolism caused by a deficiency of debranching enzyme. Different subtypes with different clinical pictures have been recognized. During childhood and early adulthood, the symptoms generally regress, and normal adulthood appears possible in most patients without symptoms or signs of cirrhosis. We report on an adult patient with GSD who developed endstage cirrhosis and a small hepatocellular carcinoma. She had GSD subtype IIIb, i.e., there were no signs of cardiomyopathy, myopathy, or neuropathy. She underwent a successful transplantation, representing the first case treated this way for this indication to our knowledge, and she is doing well after 1 year. Debranching enzyme activity was absent both in the liver and in the leukocytes before transplantation. The debranching enzyme activity remained absent in the leukocytes after transplantation. We conclude that patients with GSD type III may develop end-stage cirrhosis and hepatocellular carcinoma and therefore need hepatological follow-up during adulthood.

Obstructive hypertrophic cardiomyopathy in type III glycogen-storage disease

We present here a rare case of a patient affected by hypertrophic obstructive cardiomyopathy related to type III glycogenosis. In this patient the correct diagnosis could only be performed by endomyocardial biopsy.

The prevalence of polycystic ovaries in the hepatic glycogen storage diseases: its association with hyperinsulinism

OBJECTIVE

There has been much debate concerning the relative contribution of insulin resistance to the development of polycystic ovaries (PCO). We therefore aimed to assess ovarian morphology and insulin/androgen status in females with the hepatic glycogen storage diseases types Ia (GSD-Ia) and III (GSD-III), disorders associated with abnormalities of insulin secretion.

DESIGN

A cross-sectional study of ovarian ultrasonography, oral glucose tolerance tests (oGTTs) and single measurements of gonadotrophins and androgens were performed.

PATIENTS

Twenty-seven patients were evaluated: 13 with GSD-Ia, median age 11.2 years (range, 3.3-26.7) and 14 with GSD-III, aged 13.2 years (4.2-31.3). None had clinical signs of hyperandrogenism and only two of the 13 adults (15%) had menstrual irregularities. They were compared to 9 normal adult female controls, aged 21-28 years.

MEASUREMENTS

Ovarian morphology and volume were measured. Blood glucose and plasma insulin concentrations were measured at the beginning and end of a 2-hour oGTT. Single measures of LH, FSH, testosterone, dehydroepiandrosterone sulphate, androstenedione, IGF-I and SHBG were made on samples taken at the beginning of the oGTT.

RESULTS

In both GSD-Ia and III, all those older than 4.8 years of age had a polycystic ovarian appearance. Pre-pubertal GSD-Ia patients had lower basal and 2-hour blood glucose and plasma insulin concentrations than pre-pubertal GSD-III patients. In adults with GSD-Ia and GSD-III, although basal and 2-hour blood glucose concentrations did not differ, both basal and 2-hour plasma insulin concentrations were significantly higher than controls. Serum gonadotrophins, androgens, IGF-I and SHBG were mostly normal.

CONCLUSIONS

A polycystic ovarian appearance is a common finding in patients with glycogen storage disease even before puberty. In GSD-III and adults with GSD-Ia, this ovarian appearance was associated with hyperinsulinism, suggesting an aetiological link, but this was not the case in pre-pubertal children with GDS-Ia. Inborn errors of carbohydrate metabolism may act as useful models for examining control mechanisms of ovarian physiology and development.

[A 21-year-old man with distal dominant progressive muscle atrophy]

We report a 21-year-old man with distal dominant progressive muscle atrophy. The patient was apparently well until 17 years of age when he noted a decrease in exercise tolerance. One year later, he noted difficulty in arising his heels when the walked. He was admitted to our service for the work up in June 10, 1992. On admission, the patient was rather slender in the body build up; otherwise general physical examination was unremarkable. Upon neurologic examination, mental status and higher cerebral functions were normal. In the cranial nerves, the sternocleidomastoid muscles were atrophic bilaterally; other cranial nerves appeared intact. His gait was unstable and he showed steppage gait; walking on toes and heels were impossible. Distal dominant muscle atrophy was noted in both upper and lower extremities. Muscle strength in the deltoid, biceps brachii and triceps brachii was normal. In the lower extremities, both tibialis anterior and triceps surae muscles were weak (3/5). The iliopsoas and quadriceps femoris muscles were normal, however, the adductor muscles of the thigh showed marked weakness (2/5). Myotonia was absent. Deep reflexes were decreased; sensation was intact. Routine blood tests were unremarkable; CK was 96 IU/l, lactate 6.9 mg/dl, and pyruvate 0.61 mg/dl. After an ischemic forearm exercise test, blood lactate level rose to 22.5mg/dl (base line 11.2), and blood ammonia to 88.3 micrograms/dl (base line 71.2). EMG showed myogenic changes and myotonic discharges. A diagnostic biopsy was performed. The patient was discussed in a neurologic CPC, and the chief discussant arrived at the conclusion that the patient had type III glycogen storage disease. The differential diagnosis included rimmed vacuole type myopathy, Miyoshi type distal muscular dystrophy, Welander type muscular dystrophy, adult type acid-maltase deficiency, and lysosomal glycogen storage disease with normal acid maltase. However, characteristic clinical presentation of initial weakness in the triceps surae muscle associated with atrophy of the sternocleidomastoid muscle confirmed best of the clinical characteristics of type III glycogen storage disease; the only finding which did not fit with its diagnosis was elevation of the blood lactate level after the ischemic exercise test. The muscle biopsy specimen showed marked vacuole formation; approximately 20 to 30% of the vacuoles were rimmed vacuoles, however, the majority was not rimmed. PAS staining on an epon-embedded specimen revealed marked accumulation of PAS-positive materials in those vacuoles as well as in the interfascular space. The non-rimmed vacuoles were not positively stained in the acid-phosphatase staining, which exclude the diagnosis of acid maltase deficiency. No mitochondrial abnormalities were found.(ABSTRACT TRUNCATED AT 400 WORDS)

[Glycogenosis type III and Crohn disease with associated ankylopoietic spondylitis and secondary amyloidosis. An unusual coincidence]

We present a member of a family with glycogen deposit disease (GDD) type III (Forbes-Cori's disease) confirmed postmortem through enzymatic analysis of the hepatic and muscular tissues, coinciding with a Crohn's disease associated to ankylopoietic spondylitis, with final development of an extended secondary amiloidosis, all of these diagnosis established in life of the patient and verified in necropsy. We comment this rare finding, the absence of similar cases in the bibliography and the fortuitous nature of this association given the impossibility to suggest another relationship.

Dental and craniofacial findings in a child affected by glycogen storage disease type III

This paper reports on previously undescribed dentofacial features a child suffering from Glycogen-Storage Disease type III with hepatomegaly and hypertransaminasemia with muscular involvement. Deficient craniofacial development, reduced width of the upper jaw resulting in posterior cross-bite, and taurodontism of the primary dentition were found. Pathogenetic basis for craniofacial abnormalities is discussed. Cooperation between pediatricians and pediatric dentists is strongly recommended for an early diagnosis and treatment of the dentofacial defects of the syndrome.

A man with type III glycogenosis associated with cirrhosis and portal hypertension

Type III glycogenosis, an inherited disorder of glycogen metabolism that results from reduced or absent activity of the enzyme amylo-1,6-glycosidase (debranching enzyme), has not been frequently associated with cirrhosis and portal hypertension in adults. An adult Caucasian man with well-document type IIIa glycogenosis, who presented with a variceal hemorrhage secondary to hepatic cirrhosis, is described here. No other cause of cirrhosis was found.

Histopathological findings in the biopsied muscle of a juvenile type III glycogenosis

We report a case of juvenile type III glycogenosis that was confirmed by histopathological and biochemical studies. The histopathological findings consisted of vacuoles, periodic acid-Schiff positive materials, type 2B fiber deficiency, mildly positive acid phosphatase reaction and intensely positive non-specific esterase reaction. It is suggested that the enzyme reactions may be related to membrane-bound sacs containing glycogen.

Accumulation of glycogen in sural nerve axons in adult-onset type III glycogenosis

A 42-year-old man with adult-onset type III glycogenosis (Cori's disease) developed a gradually progressive polyneuropathy with markedly reduced activity of muscle amylo-1,6-glucosidase and glycogen accumulation within all elements of biopsied sural nerve, including axons, as shown by ultrastructural assessment.

Neuromuscular involvement in glycogen storage disease type III

Sixteen patients with glycogen storage disease type III (GSD III) aged 3 to 22 years underwent a detailed neuromuscular evaluation. A minimal impairment of skeletal muscle function was presented in eight patients, slight impairment in four and severe impairment in one patient. Serum creatinine phosphokinase (CPK) was elevated in all patients studied. In the nine patients, in whom electromyography (EMG) was performed; six exhibited a myopathic pattern while a "mixed" (neurogenic-myopathic) pattern was present in three. Muscle biopsies performed in 12 patients, revealed in all cases amylo-1,6,-glucosidase deficiency and biochemical as well as morphological evidence of glycogen accumulation. Two brothers suffered from late onset myopathy, which in the older sibling was associated with clinical, EMG and EM findings of a peripheral neuropathy. Fifteen patients had either electrocardiographic and or echographic evidence of cardiomyopathy. Observations based on this patient material suggest a widespread myopathy in GSD III patients with heterogeneous expression, while peripheral nerve involvement is rarely encountered.

Insular amyloid in a case of type III glycogenosis with a special reference to the origin of amyloid fibrils

Amyloid depositions of pancreatic islets were investigated with electron microscopy in a case of type III glycogenosis. Beta cells adjoining small amyloid depositions were shown to have cytoplasmic invaginations where closely packed amyloid fibrils were disclosed regularly orientated amyloid bundles. In the cytoplasm of the beta cells, some membrane-bounded vesicles contained amyloid fibrils and a few beta granules directly transformed into the fibrils within the vesicles. These findings indicate that, at least in this case, the beta cells play a crucial role in the formation of insular amyloid.

Peripheral nerve in type III glycogenosis: selective involvement of unmyelinated fiber Schwann cells

Electron microscopy of intramuscular nerves in biopsy material from a child with glycogenosis type III showed massive glycogen accumulation in the Schwann cells of unmyelinated nerve fibers. Other cells, including Schwann cells of myelinated fibers, perineurial cells, endoneurial fibroblasts, endothelial cells, and pericytes, were not similarly affected.

Clinical varieties of neuromuscular disease in debrancher deficiency

Two men and one woman with debrancher deficiency had symptoms and signs of neuromuscular disease. The two men had adult-onset and slowly progressive weakness, distal muscle wasting, "mixed" electromyographic patterns, and slow nerve conduction velocities; the initial diagnosis was Charcot-Marie-Tooth disease in one patient and motor neuron disease in the other. The woman had stunted growth, delayed motor milestones, and lifelong nonprogressive weakness. A muscle biopsy specimen showed severe vacuolar myopathy in all three cases. The glycogen concentration was increased threefold to sixfold and had an abnormal iodine spectrum. Anaerobic glycolysis in vitro showed impaired use of endogenous and exogenous glycogen but normal use of hexose-phosphate glycolytic intermediates. These three cases illustrated the clinical variety of neuromuscular disease in debrancher deficiency. In patients with weakness of adult onset, the diagnosis is impossible to make without performing a muscle biopsy.

[Morphology of metabolic myopathies]

While muscular lesions in endocrine or metabolic diseases are fairly common primary metabolic myopathies are rare. In these, the metabolic fault is in the muscle fibre itself, which takes on a vacuolated appearance. In the majority of these myopathies there is an abnormality of the glycogen or fat metabolism due to the absence of a specific enzyme in most cases. By contrast, the pathogenesis of the so called mitochondrial myopathies is not yet well understood.