Von Gierke Disease, (Glycogen Storage Disorder I) A Simple Guide To The Condition, Diagnosis, Treatment And Related Conditions

This book describes Von Gierke Disease, Diagnosis and Treatment and Related DiseasesGlucose-6-phosphatase deficiency (G-6-P Deficiency) is the cause of type Ia and should not be confused with glucose-6-phosphate dehydrogenase deficiency (G6PD Deficiency). Von Gierke disease is a disorder in which the body cannot break down glycogen. Glycogen is a storage form of sugar (glucose) that is amassed in the liver and muscles.
It is normally broken down into glucose to give the patient more energy when the patient needs it. Von Gierke disease is also termed the Type I glycogen storage disease (GSD I). Von Gierke's disease signifies the largest cluster of glycogen storage disorders (GSDs). There is an enzyme defect in glucose-6-phosphatase so that glucose-6-phosphate cannot be converted into free glucose but is metabolized to lactic acid or integrated into glycogen.
The liver and kidneys are affected and hypoglycemia is a major feature. Large quantities of glycogen are formed and stored in liver cells, renal and intestinal mucosa cells. The liver and kidneys become swollen. Abnormalities of lipids may cause xanthoma (yellow nodule on the skin, caused by deposition of lipids) formation. Uric acid is often raised and may cause medical gout. Galactose, fructose and glycerol are metabolized to lactate.
The raised blood lactate levels cause metabolic acidosis. Type Ia has glucose-6-phosphatase deficiency in the liver and type Ib has normal activity. Causes:Von Gierke disease is inherited as an autosomal recessive disorder. Von Gierke disease happens when the body lacks the protein (enzyme) that breaks down glycogen into glucose. This produces abnormal quantities of glycogen to accumulate in certain tissues.
When glycogen is not broken down suitably, it results in low blood sugar. Von Gierke disease is inherited, which indicates it is passed down through families. If both parents have a nonworking copy of the gene linked to this disorder, each of their children has a 25% (1 in 4) chance of forming the disease. Symptoms1. Constant hunger2. Easy bruising and nosebleeds3. Fatigue4. Irritability5. Puffy cheeks, thin chest and limbs, and swollen bellyThe manifestation is normally soon after birth.
Shortly after birth, hypoglycemia and lactic acidosis often produce convulsions. More moderate hypoglycemia can produce:1. Irritability, 2. Pallor, 3. Cyanosis, 4. Hypotonia, 5. Tremors, 6. Loss of consciousness, and7. Apnea. In the first weeks of life the liver is normal in size but it expands to produce marked abdominal distension. Growth is retarded and height is normally below the third percentile.
Mental development is normal. DiagnosisThe doctor will do a physical examination showing:1. Delayed puberty2. Enlarged liver3. Gout4. Inflammatory bowel disease5. Liver tumors6. Severe low blood sugar7. Stunted growth or failure to growChildren with this disorder are normally diagnosed before age 1. Blood glucose and pH are normally low with raised lactate, uric acid, triglyceride and cholesterol.
Renal function tests: the blood creatinine and urea may be raised. FBC: anemiaDiagnosis is made by:1. Biopsy of liver or kidney2. Genetic testingTreatmentThe purpose of treatment is to prevent low blood sugar. The patient should eat often during the day, especially carbohydrates. Older children and adults may take corn-starch by mouth to raise their carbohydrate intake. In some children, a feeding tube is inserted through their nose into the stomach to give sugars or cornstarch throughout the night.
The doctor may also give medicines to treat kidney disease, high lipids, gout. Nasogastric tube feeding is needed continually by all infants. TABLE OF CONTENTIntroductionChapter ...