2026-06-11 | Hepatocyte-specific Cas9-mediated editing of G6pc and Slc37a4 elicits comparable biochemical and regulatory responses between glycogen storage disease (GSD) type Ia and Ib mice.
Glycogen storage disease type I (GSD I) is an autosomal recessive inborn error of carbohydrate metabolism. Patients with GSD type Ia and Ib exhibit overlapping and distinct symptoms and complications. Notably, GSD Ia patients show more severe hypertriglyceridemia and higher risk of hepatic tumors than GSD Ib patients. Given the liver's pivotal role in these processes, this study utilized hepatocyte-specific CRISPR/Cas9-mediated somatic gene editing to explore the pathophysiological and biochemical adaptations in hepatic GSD Ia and Ib side-by-side. Additionally, hepatic histology, transcriptomics, and proteomics analysis was performed. Compared to controls, hepatic GSD Ia and Ib mice showed hepatomegaly, fasting hypoglycemia, hyperlactatemia, and increased uric acid in plasma, which was somewhat more pronounced in GSD Ia than Ib. Both GSD I subtypes showed similar reductions in hepatic acetyl-CoA precursor pool enrichment and increases in de novo biosynthesis of hepatic stearate and oleate. Interestingly, only GSD Ia mice showed mildly elevated plasma triglyceride and hepatic phosphate sugars. Metabolic changes were reflected at the transcriptomic and proteomic levels, with largely similar responses between GSD Ia and Ib livers. Moreover, altered mRNAs and protein levels related to nucleotide-binding oligomerization domain (NOD) signaling pathways, infection and inflammation, liver disease, and chemical carcinogenesis were somewhat more pronounced in hepatic GSD Ia than in GSD Ib mice. Overall, the metabolic disturbance was more severe in hepatocyte-specific GSD Ia than in GSD Ib mice, consistent with the clinical phenotype in patients. The metabolic disorders and specific metabolites, genes, and proteins identified in this study provided new insights into the pathophysiological and biochemical phenotypes of GSD I subtypes in the liver.
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2026-03-20 | Infantile extreme hypertriglyceridemia diagnosed as glycogen storage disease type Ia: A case report.
Glycogen storage disease type Ia (GSD Ia) typically presents with fasting hypoglycemia and hyperlipidemia. Atypical infantile presentations can delay diagnosis. We report an infant with extreme hypertriglyceridemia ultimately diagnosed as GSD Ia. A 5-month-old girl presented with poor appetite, growth retardation, hepatomegaly, and extreme hypertriglyceridemia (72 mmol/L), hypercholesterolemia, elevated transaminases, hyperuricemia, and hyperlactatemia, but initial normal blood glucose. Initial differentials included familial hypertriglyceridemia, but metabolic screening was normal. Whole-exome sequencing confirmed GSD Ia with compound heterozygous G6PC mutations (c.648G>T and c.814G>T). Initial lipid-lowering (low-fat diet, fenofibrate, omega-3, plasma exchange) reduced triglyceride. Post-diagnosis, she received lactose-free formula with frequent feeds and nocturnal nutrition; uncooked cornstarch was introduced at 6 months, though adherence was initially poor. Metabolic control was unstable until age 2 due to poor adherence. After 24 months of structured cornstarch therapy, fasting glucose normalized (4.2-6.6 mmol/L), triglycerides decreased (1.8-6.7 mmol/L), and catch-up growth occurred (height Z-score from -3.9 to -2.2 by 36 months). GSD Ia should be considered in infantile extreme hypertriglyceridemia with growth retardation, even without classic hypoglycemia. Sustained metabolic control requires multidisciplinary strategies addressing both biochemical and adherence barriers.
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2026-01-07 | Congenital nephrotic syndrome in a newborn with glycogen storage disease and Wilms tumor 1 (WT1) mutation.
Genetic disorders in neonates often present with overlapping clinical features, posing significant diagnostic challenges. Glycogen storage diseases (GSD) disrupt glycogen metabolism, leading to energy deficits. Pathogenic variants in the Wilms tumor 1 (WT1) gene represent a rare but significant cause of early-onset steroid-resistant nephrotic syndrome (SRNS), associated with a broad range of both kidney and extrakidney phenotypic manifestations. The coexistence of these genetic diseases in a single patient has not been previously reported. Herein, we present a case of a newborn with symptomatic hypoglycemia and metabolic acidosis that was transferred to the Neonatal Intensive Care Unit. During hospitalization, he developed hyponatremia and nephrotic-range proteinuria, a genetic test was performed, and he was transferred to the nephrology unit. Genetic analysis identified a compound homozygous mutation (c.247 C > T) in the G6PC gene, confirming glycogen storage disease type 1a (GSD-1a) and a pathogenic WT1 mutation (c.1400G > A) associated with Denys-Drash syndrome. This case highlights the importance of a multidisciplinary approach in the evaluation and management of neonates with a complex combination of genetically-determined conditions.
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