Mutation spectrum of type I glycogen storage disease in Hungary

Summary We performed mutation analysis in 12 Hungarian type I glycogen storage disease (GSD I) patients in order to determine the mutation spectrum. All patients were clinically classified as GSD Ia. Nine patients carried biallelic G6PC mutations (p.Q27fsX35, p.D38V, p.W70X, p.K76N, p.W77R, p.R83C, p.E110Q, p.G222R), with E110Q reported only in Hungary. However, three patients displayed two common G6PT1 (SLC37A4) mutations (p.L348fsX400, p.C183R) which were originally described in association with GSD Inon-a. Review of the literature and our data show that G6PT1 mutations are not associated with neutropenia and related clinical findings in approximately 10% of these cases. Homozygosity for the truncating G6PT1 mutation p.L348fsX400 can be observed with and without neutropenia, indicating that one or more modifiers of the action of G6PT1 exist. Our data are suitable to provide DNA-based and thus noninvasive confirmation of diagnosis in Hungarian patients with this disorder.     

Utilization of cornstarch in glycogen storage disease type Ia

OBJECTIVE: Uncooked cornstarch (UCCS) is used widely for the treatment of patients with glycogen storage disease type I (GSD-I). Previous studies suggested that glucose absorption may be impaired in GSD-I. In order to measure utilization of UCCS in young adults with GSD-Ia and healthy controls, we used a C-breath test based on the natural enrichment of C in UCCS. DESIGN: Open, not randomized, prospective interventional study. METHODS: Following 1 g/kg UCCS, we studied eight subjects with GSD-Ia (7 males, 1 female; mean age 28.3 years, range 16-42 years) and 15 healthy controls (10 males, 5 females; mean age 23.5 years, range 19-36 years). Breath samples for analysis of CO enrichment were collected at baseline and at 30-min intervals for 6 h or until hypoglycaemia occurred. Indirect calorimetry was used to measure respiratory gas exchange. Intermediate metabolites, lipids and glucose were measured in plasma. Breath H concentrations were measured as an indicator of malabsorption. RESULTS: Cumulative utilization over 6 h was significantly higher in controls (18.35 +/- 6.2% of total carbohydrate intake) than in subjects with GSD-Ia (11.5 +/- 4.7%) (P < 0.02). However, utilization of UCCS was virtually identical up to 2.5 h. Two subjects with GSD-Ia fulfilled the criteria for malabsorption. CONCLUSIONS: Starch digestion and absorption are not impaired in GSD-Ia. However, overall utilization of UCCS appears to be lower in GSD-Ia, which is most likely secondary to perturbed intermediary metabolism. There are important implications for treatment of this disorder. Ways to improve the efficacy of UCCS in GSD-I are needed.     

Unreliability of platelet glucose-6-phosphatase for the diagnosis of glycogen storage disease type Ia

Summary The diagnosis of glycogen storage disease type Ia currently uses enzyme analysis of liver tissue. This requires liver biopsy in the at-risk neonate or fetus. Conflicting reports have appeared in the literature on the use of peripheral platelet glucose-6-phosphatase activity for the diagnosis of this disorder. We have applied a sensitive radiometric assay system to the measurement of glucose-6-phosphatase activity in peripheral platelets. Two families with affected members were analysed, revealing no differences in glucose-6-phosphatase activity as compared with control values. Platelet measurement of glucose-6-phosphatase does not appear to be useful for the diagnosis of glycogen storage disease type Ia.     

In search of proof-of-concept: gene therapy for glycogen storage disease type Ia

The emergence of life threatening long-term complications in glycogen storage disease type Ia (GSD-Ia) has emphasized the need for new therapies, such as gene therapy, which could achieve biochemical correction of glucose-6-phosphatase deficiency and reverse clinical involvement. We have developed gene therapy with a novel adeno-associated virus (AAV) vector that: 1) prevented mortality and corrected glycogen storage in the liver, 2) corrected hypoglycemia during fasting, and 3) achieved efficacy with a low number of vector particles in G6Pase-deficient mice and dogs. However, the gradual loss of transgene expression from episomal AAV vector genomes eventually necessitated the administration of a different pseudotype of the AAV vector to sustain dogs with GSD-Ia. Further preclinical development of AAV vector-mediated gene therapy is therefore warranted in GSD-Ia.     

Hepatocellular carcinoma in glycogen storage disease type Ia: A case series

Summary We present a series of 8 patients (6 males, 2 females) with hepatocellular carcinoma (HCC) and glycogen storage disease type Ia (GSD Ia). In this group, the age at which treatment was initiated ranged from birth to 39 years (mean 9.9 years). All patients but one were noncompliant with treatment. Hepatic masses were first detected at an age range of 13–45 years (mean 28.1 years). Age at diagnosis of HCC ranged from 19 to 49 years (mean 36.9 years). Duration between the diagnosis of liver adenomas and the diagnosis of HCC ranged from 0 to 28 years (mean 8.8 years, SD=11.5). Two patients had positive hepatitis serologies (one hepatitis B, one hepatitis C). α-Fetoprotein (AFP) was normal in 6 of the 8 patients. Carcinoembryonic antigen (CEA) was normal in the 5 patients in which it was measured. Current guidelines recommend abdominal ultrasonography with AFP and CEA levels every 3 months once patients develop hepatic lesions. Abdominal CT or MRI is advised when the lesions are large or poorly defined or are growing larger. We question the reliability of AFP and CEA as markers for HCC in GSD Ia. Aggressive interventional management of masses with rapid growth or poorly defined margins may be necessary to prevent the development of HCC in this patient population.     

Mallory bodies in a patient with type Ia glycogen storage disease

Mallory bodies were determined by light microscopy and confirmed by electron microscopy in the liver of a 37-yr-old woman with type Ia glycogen storage disease. They were found mainly in the swollen hepatocytes of the centrilobular region in the liver associated with periportal and centrilobular pericellular fibrosis. Ultrastructurally, the shape of small circular structures found in the Mallory body was similar to that of the circularly disorganized rough endoplasmic reticulum seen around the Mallory body. Although Mallory bodies are seen in several liver diseases other than alcoholic liver injury, there has been only one report of finding them in the liver in type I glycogen storage disease.     

Resection of hepatocellular adenoma in patients with glycogen storage disease type Ia

BACKGROUND/AIMS: Because dietary modifications have prolonged the life expectancy of patients with glycogen storage disease type Ia (GSD Ia), the incidence of hepatocellular adenoma (HCA) to carcinoma (HCC) transformation is increasing. The objective of this retrospective study is to assess the safety and effectiveness of HCA resection in GSD Ia patients. METHODS: Clinicopathologic, peri-operative, and long-term data were reviewed from patients who underwent HCA resection. Comparisons were made with Fisher's exact, Mann-Whitney U, and log-rank tests; survival was estimated with Kaplan-Meier analysis. RESULTS: From 1998 to 2006, 38 patients underwent HCA resection. Seven (22%) had GSD Ia. Post-operative mortality occurred in one GSD Ia patient. GSD Ia patients had greater morbidity (86% vs. 20%) and shorter time to adenoma progression (median 23 months vs. not yet reached) after partial hepatectomy compared to the general population (p<0.05). Six GSD Ia patients had no evidence of HCC and recovered after resection without long-term morbidity. Three GSD Ia patients underwent liver transplantation 77, 32, and 23 months after adenoma resection. CONCLUSIONS: Despite substantial morbidity, partial hepatectomy is feasible in GSD Ia patients and is an effective intermediate step in the prevention of HCC until definitive treatment with liver transplantation.     

A case of type Ia glycogen storage disease complicated by hepatic adenoma

A 31-year-old male patient with type Ia glycogen storage disease was admitted to our department complaining of general fatigue and right hypochondriac pain. He exhibited massive hepatomegaly with systemic hypoglycemia, lactic acidosis, hyperuricemia, hyperpyruvatemia and hyperlipemia. The failure of blood glucose levels to increase after a glucagon loading test, and a reduced lactate level on glucose tolerance test were also observed. Various imaging techniques suggested hepatic adenoma with hemorrhage in the tumor, which was confirmed histologically. There was a complete absence of glucose 6-phosphatase activity, as determined by an enzyme assay on resected liver specimens, which proved the case to be type Ia glycogen storage disease. We also reviewed all previously reported cases of hepatic tumor and glycogen storage diseases. We conclude that, since hepatic adenoma is not rare in this disease, and is complicated by hemorrhage, rupture and malignancy, careful follow-ups are necessary.     

Case of cholangiocellular carcinoma in a patient with glycogen storage disease type Ia

Glycogen storage disease (GSD) type Ia is caused by a deficiency in glucose‐6‐phosphatase. Long‐term complications, including renal disease, gout, osteoporosis and pulmonary hypertension, develop in patients with GSD type Ia. In the second or third decade, 22–75% of GSD type Ia patients develop hepatocellular adenoma (HCA). In some of these patients, the HCA evolves into hepatocellular carcinoma. However, little is known about GSD type Ia patients with HCA who develop cholangiocellular carcinoma (CCC). Here, we report for the first time, a patient with GSD type Ia with HCA, in whom intrahepatic CCC was developed.     

Molecular genetic analysis of glycogen storage disease type Ia in 26 Chinese patients

Sequence analysis of 26 patients from Mainland China with glycogen storage disease type Ia revealed a high frequency of two mutations in the glucose-6-phosphatase gene. These mutations, 727G>T and R83H, were also found to be in linkage disequilibrium with a polymorphism at position 1176. These findings have implications for carrier detection and prenatal diagnosis of this disease in the Chinese population.     

Long-term outcome of liver transplantation in patients with glycogen storage disease type Ia

Liver transplantation may be indicated in patients with GSD type Ia when dietary treatment fails or when hepatic adenomas develop, because they carry a risk of liver cancer or severe intratumoral haemorrhage. Published reports on the results of liver transplantation in patients with GSD Ia include 10 patients and provide little information on long-term outcome. In particular, it is not known whether liver transplantation prevents renal failure due to focal segmental glomerulosclerosis. We report here on 3 patients with GSD Ia in whom liver transplantation was performed at 15, 17 and 23 years of age because of multiple hepatic adenomas in all 3 patients with a fear of malignant transformation, and of poor metabolic balance and severe growth retardationin the youngest one. Renal function was normal in all patients. During the 6–8 years following transplantation, the quality of life has initially greatly improved, with none of the previous dietary restraints and a spectacular increase in height. However, long-term complications included chronic hepatitis C in one patient, gouty attacks in another and focal segmental glomerulosclerosis with progressive renal insufficiency in the third. These results: (1) confirm that liver transplantation restores a normal metabolic balance in patients with GSD Ia, allows catch-up growth and improves the quality of life; (2) suggest that liver transplantation may be considered in teenagers with unresectable multiple adenomas because of a lack of clear-cut criteria to detect malignant transformation early; and (3) suggest that liver transplantation does not prevent focal segmental glomerulosclerosis associated with GSD Ia.     

Markedly elevated serum biotinidase activity may indicate glycogen storage disease type Ia

We report two children who presented with symptoms suggestive of biotinidase deficiency. Rather than deficiency, markedly elevated serum biotinidase activities were found. Based upon literature reports of elevated biotinidase activities in children with glycogen storage disease (GSD) type Ia, we considered the latter in our differential diagnosis and subsequently confirmed GSD type Ia in both patients by enzymatic testing. GSD type Ia should be considered in children with markedly elevated serum biotinidase activity.     

Short-term effect of captopril on microalbuminuria in children with glycogen storage disease type Ia

Early signs of renal dysfunction in glycogen storage disease type Ia (GSD Ia) are glomerular hyperfiltration and proteinuria. In a non-randomized study, the effect of captopril on the improvement of proteinuria in GSD Ia patients with microalbuminuria was investigated. A positive effect has been shown for the insulin-dependent diabetes mellitus patients. Microalbuminuria was defined as albumin/creatinine ratio (mg/mmol) more than 2.5 in spot urine. Nineteen (52.7%) out of 36 patients had microalbuminuria, and 8 patients received captopril at a dose of 1mg/kg per day. Microalbuminuria was evaluated periodically during the follow-up period. Of the captopril-treated patients, one was lost to follow-up. In the remaining 7 patients, urinary albumin excretion normalized in 3 patients (42.9%) and decreased at least by 50% in another 3 patients (42.8%) after 6 months of treatment. One patient, who was the oldest, did not have any benefit. In untreated patients, only two patients had a decrease in microalbuminuria of more than 50%. Patients with microalbuminuria had significantly higher blood lactate (p<0.05) and plasma triglyceride (p<0.01) concentrations and significantly lower blood bicarbonate concentration (p<0.05) than those patients without it. Additionally, the patients with microalbuminuria had been diagnosed earlier than those without microalbuminuria (p<0.05). Patients with microalbuminuria have more severe clinical and laboratory findings than those without microalbuminuria. Captopril at a dose of 1 mg/kg per day seems to be effective in at least 50% of GSD Ia patients with microalbuminuria.     

Perioperative management of benign hepatic tumors in patients with glycogen storage disease type Ia

Glycogen storage disease type Ia (GSD-Ia; von Gierke disease) is an inherited disorder caused by glucose-6-phosphatase deficiency, and there have been some reports of hepatic tumors in patients with this disease. We report two patients with benign hepatic tumors with GSD-Ia. One is a 19-year-old man who underwent segmentectomy 4 for a focal nodular hyperplasia, and the other is a 31-year-old woman who underwent segmentectomies 3, 5, and 6 for hepatic adenomas. Two significant perioperative complications, resulting from the carbohydrate metabolic disorders, hypoglycemia and metabolic acidosis, occurred in both patients. We managed the metabolic complications successfully by administering a sufficient volume of glucose intravenously. Close perioperative monitoring of blood glucose and lactate concentrations is essential in the perioperative management of patients with GSD-Ia. The intravenous administration of glucose, starting with a smaller dose and then increasing the dose, is adequate management for lactic acidosis with or without hypoglycemia during the perioperative period.