Diabetes mellitus in a patient with glycogen storage disease type Ia: a case report

Endocrine involvement in hepatic glycogen storage diseases: pathophysiology and implications for care

Hepatic glycogen storage diseases constitute a group of disorders due to defects in the enzymes and transporters involved in glycogen breakdown and synthesis in the liver. Although hypoglycemia and hepatomegaly are the primary manifestations of (most of) hepatic GSDs, involvement of the endocrine system has been reported at multiple levels in individuals with hepatic GSDs. While some endocrine abnormalities (e.g., hypothalamic‑pituitary axis dysfunction in GSD I) can be direct consequence of the genetic defect itself, others (e.g., osteopenia in GSD Ib, insulin-resistance in GSD I and GSD III) may be triggered by the (dietary/medical) treatment. Being aware of the endocrine abnormalities occurring in hepatic GSDs is essential (1) to provide optimized medical care to this group of individuals and (2) to drive research aiming at understanding the disease pathophysiology. In this review, a thorough description of the endocrine manifestations in individuals with hepatic GSDs is presented, including pathophysiological and clinical implications.

Novel mutation of SLC37A4 in a glycogen storage disease type Ib patient with neutropenia, horseshoe kidney, and arteriovenous malformation: a case report

Glycogen storage disease type Ib (GSDIb) is an autosomal recessive disorder caused by mutations of SLC37A4 gene, which encodes glucose 6-phosphate translocase (G6PT). Malfunction of G6PT leads to excessive fat and glycogen in liver, kidney, and intestinal mucosa. The clinical manifestations of GSD1b include hepatomegaly, renomegaly, neutropenia, hypoglycemia, and lactic acidosis. Furthermore, the disorder may result in severe complications in long-term including inflammatory bowel disease (IBD), hepatocellular adenomas (HCA), short stature, and autoimmune disorders, which stem from neutropenia and neutrophil dysfunction. Here, we represent a novel mutation of SLC37A4 in a 5-month girl who has a history of hospitalizations several times due to recurrent infection and her early presentations were failure to thrive and tachypnea. Further investigations revealed mild atrial septal defect, mild arteriovenous malformation from left lung, esophageal reflux, Horseshoe kidney, and urinary reflux in this patient. Moreover, the lab tests showed neutropenia, immunoglobulin (Ig) G and IgA deficiency, as well as thrombocytosis. Whole exome sequencing revealed c.1245G > A P.W415 homozygous mutation in SLC37A4 gene and c.580G > A p.V1941 heterozygous mutation in PIK3CD gene. This study shows that manifestations of GSD1b may not be limited to what was previously known and it should be considered in a wider range of patients.

A glycogen storage disease type 1a patient with type 2 diabetes

Background

Glycogen storage disease type 1a (GSD1a) is an inborn genetic disease caused by glucose-6-phosphatase-α (G6Pase-α) deficiency and is often observed to lead to endogenous glucose production disorders manifesting as hypoglycemia, hyperuricemia, hyperlipidemia, lactic acidemia, hepatomegaly, and nephromegaly. The development of GSD1a with diabetes is relatively rare, and the underlying pathogenesis remains unclear.

Case presentation

Here we describe a case of a 25-year-old Chinese female patient with GSD1a, who developed uncontrolled type 2 diabetes mellitus (T2DM) as a young adult. The patient was diagnosed with GSD1a disease at the age of 10 and was subsequently treated with an uncooked cornstarch diet. Recently, the patient was treated in our hospital for vomiting and electrolyte imbalance and was subsequently diagnosed with T2DM. Owing to the impaired secretory function of the patient’s pancreatic islets, liver dysfunction, hypothyroidism, severe hyperlipidemia, and huge hepatic adenoma, we adopted diet control, insulin therapy, and hepatic adenoma resection to alleviate this situation. The WES discovered compound heterozygous mutations at the exon 5 of G6PC gene at 17th chromosome in the patient, c.648G>T (p.L216 L, NM_000151.4, rs80356484) in her father and c.674T>C (p.L225 P, NM_000151.4, rs1555560128) in her mother. c.648G>T is a well-known splice-site mutation, which causes CTG changing to CTT at protein 216 and creates a new splicing site 91 bp downstream of the authentic splice site, though both codons encode leucine. c.674T>C is a known missense mutation that causes TGC to become CGC at protein 225, thereby changing from coding for leucine to coding for proline.

Conclusion

We report a rare case of GSD1a with T2DM. On the basis of the pathogenesis of GSD1a, we recommend attentiveness to possible development of fasting hypoglycemia caused by GSD and postprandial hyperglycemia from diabetes. As the disease is better identified and treated, and as patients with GSD live longer, this challenge may appear more frequently. Therefore, it is necessary to have a deeper and more comprehensive understanding of the pathophysiology of the disease and explore suitable treatment options.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01344-3.

Type la glycogen storage disease complicated with diabetes mellitus: the role of flash continuous glucose monitoring

A 22-year-old woman with type Ia glycogen storage disease was referred to the endocrinology department with new-onset diabetes mellitus-glycated haemoglobin (HbA1c) of 8.2%. She had suffered from repeated bouts of hypoglycaemia since the first days of her life. The diagnosis was made at 5 months old, after clinical investigations revealed mixed dyslipidaemia, lactic acidosis and hepatomegaly. Compound heterozygosity was documented at the age of 4. The basis of her initial treatment was starch and reinforced soy milk, ingested multiple times a day and night. The patient suffered from obesity since childhood. This case shows a rare association between glycogen storage disease type Ia and diabetes mellitus. A multidisciplinary approach was implemented. Through diet and use of flash continuous glucose monitoring, we were able to improve patient's adherence and metabolic profile. Hypoglycaemia and hyperglycaemia risk significantly decreased; 86% time in range (70-180 mg/dL), 6% hypoglycaemia and 6.3% HbA1c in recent evaluations.

SGLT2 inhibition alleviated hyperglycemia, glucose intolerance, and dumping syndrome-like symptoms in a patient with glycogen storage disease type Ia: a case report

Background

Glycogen storage disease (GSD) type Ia is a glycogenesis disorder with long-term complications such as hepatomegaly and renal dysfunction and is caused by congenital loss of glucose-6-phosphatase (G6Pase) expression. G6Pase is essential for the final step of gluconeogenesis and glycogenolysis, and its deficiency causes clinical hypoglycemia in the fasting state during infancy. Contrastingly, patients also show blood glucose trends and glucose intolerance similar to those in type II diabetes. Owing to the contrasting presentation of hypoglycemia with glucose intolerance, glucose control in patients remains a challenge, requiring management of both fasting hypoglycemia and post-prandial hyperglycemia.

Case presentation

The patient was a 45-year old Asian (Japanese) woman who showed disease onset at 3 years of age, when hypoglycemia and hepatomegaly were observed, and GDS type Ia was diagnosed by the lack of G6Pase activity. Over the past 45 years, she presented hyperglycemia and dumping syndrome like symptoms (a feeling of fullness, even after eating just a small amount, abdominal cramping, nausea, sweating, flushing, or light-headedness and rapid heartbeat) at 2 hours after food intake. Her liver and kidney dysfunction also worsened over time. Treatment with exercise combined with a sodium-glucose co-transporter 2 inhibitor and an alpha glucosidase inhibitor alleviated her glucose intolerance and dumping syndrome-like symptoms, without increasing hypoglycemic events.

Conclusion

This case suggests SGLT2 inhibitor as a promising candidate for treating glucose intolerance in GSD type Ia without worsening of hypoglycemia.

Secondary diabetes as a rare complication of glycogen storage disease 1a: case report and review of literature

Glycogen storage diseases (GSDs) are disorders of carbohydrate metabolism and hypoglycemia is their hallmark. Secondary diabetes with glycogen storage disease, which seems rather paradoxical, has been rarely reported. A 13-year-old girl previously diagnosed to have GSD 1a presented to the emergency with multiple episodes of vomiting and loss of consciousness. She had hyperglycemia, ketonuria, hyperlactatemia and metabolic acidosis, suggestive of diabetic ketosis with acidosis possibly contributed by both high serum lactate and serum ketones. Her glycated hemoglobin was high, with detectable serum insulin levels, which suggested secondary diabetes in the background of GSD Ia. Her management posed a therapeutic challenge. She was managed with insulin and achieved good glycemic control. We wish to conclude that GSD may rarely lead to secondary diabetes as a complication and the management is complex owing to the nature of the disease. Insulin remains the mainstay of the treatment.

Hepatic and neurobiological effects of foetal and breastfeeding and adulthood exposure to methylmercury in Wistar rats

Methylmercury (MeHg) is an organic bioaccumulated mercury derivative that strongly affects the environment and represents a public health problem primarily to riparian communities in South America. Our objective was to investigate the hepatic and neurological effects of MeHg exposure during the phases foetal and breast-feeding and adult in Wistar rats. Wistar rats (n = 10) were divided into 3 groups. Control group received mineral oil; The simple exposure (SE) group was exposed only in adulthood (0.5 mg/kg/day); and double exposure (DE) was pre-exposed to MeHg 0.5 mg/kg/day during pregnancy and breastfeeding (±40 days) and re-exposed to MeHg for 45 days from day 100. After, we evaluated possible abnormalities. Behavioral and biochemical parameters in liver and occipital cortex (CO), markers of liver injury, redox and AKT/GSK3β/mTOR signaling pathway. Our results showed that both groups treated with MeHg presented significant alterations, such as decreased locomotion and exploration and impaired visuospatial perception. The rats exposed to MeHg showed severe liver damage and increased hepatic glycogen concentration. The MeHg groups showed significant impairment in redox balance and oxidative damage to liver macromolecules and CO. MeHg upregulated the AKT/GSK3β/mTOR pathway and the phosphorylated form of the Tau protein. In addition, we found a reduction in NeuN and GFAP immunocontent. These results represent the first approach to the hepatotoxic and neural effects of foetal and adult MeHg exposure.