Patients with glycogen storage disease type I are unable to release glucose from glycogen. Because free glucose is the product of the hepatic glucose-6 phosphatase reaction, either type leads to accumulation of liver glycogen, accompanied by fasting hypoglycemia. Hepatomegaly is the clinical hallmark of disease. They cannot maintain their blood glucose levels and within a few hours after eating develop hypoglycemia (low blood sugar). The low levels of glucose in the blood of these patients often result in chronic hunger, fatigue, and irritability that is especially noticeable in infants. Symptoms of hypoglycemia only begin to appear when the interval between feedings increases and the infant sleeps through the night or when an illness prevents normal feeding routine. If the blood sugar falls to a low enough point, some patients may experience seizures. Patients can develop frequent bacterial and fungal infections, due to abnormal functioning of the white blood cells. They may also develop chronic pancreatitis, chronic inflammatory bowel disease, and Crohn's disease. Recurrent infections, including severe oral ulceration and abscesses, are associated with a neutropenia and neutrophil dysfunction.
Diagnosis
Diagnostic recommendations
Additional Information
- Glycogen Storage Disease Type I, eMedicine
- Glycogen Storage Disease Type Ia, eMedicine
- Glycogen Storage Disease Type Ib, eMedicine
- Glycogen Storage Disease, type 1, ORPHANET
- Glycogen Storage Disease, The University of Kansas Medical Center
- Glycogen Storage Disease Type I, Health on the Net Foundation
- Glicogenosi, Telethon
Diagnostic laboratories
Clinical:
- Glycogen storage disease type 1, ORPHANET
- Glycogen storage disease type 1, eMedicine
- Glycogen storage disease type 1b, eMedicine
Genetic:
- Laboratorio Diagnosi Pre-Postnatale delle Malattie Metaboliche - Istituto Giannina Gaslini (Genova), Italy, EDDNAL
- Klinische Genetica / Sectie DNA Diagnostiek - Academisch Ziekenhuis Groningen, Netherlands, EDDNAL
- North Trent Molecular Genetics Service - Sheffield Children's NHS Trust (Sheffield), UK, EDDNAL
- North East Thames Regional Clinical Molecular Genetics Laboratory (London), UK, EDDNAL
- Glycogen Storage Disease Type 1b, GeneTest
Therapeutic options
- The dietary treatment corrects hypoglycemia (frequent meals, nocturnal enteral feeding through a nasogastric tube, later oral addition of uncooked starch), acidosis (restricted fructose and galactose intake) and hepatic complications (adenomas). Liver transplantation, performed on the basis of the rare but possible transformation of adenomas into hepatocarcinoma, corrects hypoglycemia.
- Glycogen storage disease type I, eMedicine
- Glycogen storage disease type 1b, eMedicine