A CASE OF LATE-ONSET DIAGNOSIS: GLYCOGEN STORAGE DISEASE TYPE IA (VON GIERKE'S DISEASE) IN A 28-YEAR-OLD FEMALE-CASE REPORT

Introduction: Glycogen Storage Disease Type Ia (GSD Ia)
is an autosomal recessive disorder with a rare incidence and an
enzymatic deficiency of glucose-6-phosphatase, which results in
gluconeogenesis and glycogenolysis impairment. The condition tends
to present in infancy with acute fasting hypoglycemia and lactic
acidosis. Diagnosis in adults is infrequent and often delayed because
of non-specific clinical manifestations. Case Presentation: A case of
a 28-year-old woman who came with altered sensorium and a history
of chronic hypoglycemia. The clinical examination was notable for
short stature, doll like face, and enormous hepatomegaly.
Biochemical studies revealed severe hypoglycemia (32 mg/dL), lactic
acidosis, hypertriglyceridemia, and hyperuricemia. There was a high
suspicion of an inborn error of metabolism. Genetic testing revealed a
homozygous pathogenic mutation in the G6PC gene, confirming
GSD Ia. Management and Outcome: The histopathology report
revealed hepatocytes with ballooned, pale cytoplasm consistent with
massive glycogen storage, in line with a glycogen storage disease.
The final diagnosis was confirmed by the hepatic tissue enzyme
assay, where there was a near-total deficiency of glucose-6
phosphatase enzyme activity at <0.1 µmol/min/g of liver tissue (usual
reference range: 1.5 - 3.5 µmol/min/g). This result is diagnostic of
Glycogen Storage Disease Type Ia. After stabilizing, the patient was
switched to an ordered dietary regimen. This consisted of regular,
small feedings and bedtime administration of uncooked cornstarch.
She was also started with Allopurinol for hyperuricemia and
discharged stable after intensive dietary instruction. Conclusion:
This case shows that GSD Ia may remain undiagnosed until
adulthood. The detection by adult practitioners is important to
prevent metabolic crisis and allow proper long term management.
Keywords: Glycogen Storage Disease Type Ia; Von Gierke’s
Disease; Glucose-6-phosphatase deficiency; Inborn errors of
metabolism; Hypoglycemia; Hepatomegaly; Lactic acidosis;
Hyperuricemia; Hypertriglyceridemia; Case report