Glycogen storage disease type I
Introduction
Introduction to glycogen storage disease type I Glycogen storage disease is a disease caused by excessive metabolism of glycogen in tissues due to metabolic disorders of hereditary glycogen. Glycogen storage disease type I is also known as VonGeirk disease, glucose-6-phosphatase deficiency. The disease is autosomal recessive, both sexes can be rickets. Mainly manifested as hypoglycemia, liver, acidosis, hyperlipidemia, hyperuricemia, hyperlactosis, coagulopathy, developmental delay and other clinical symptoms. The nervous system of glycogen storage disease type I is mainly caused by dyskinesia and developmental delay caused by muscle weakness, and the intelligence is low. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of infection: non-infectious Complications: hypoglycemia
Cause
Glycogen storage disease type I etiology
(1) Causes of the disease
The glycogen storage disease type I is caused by a deficiency in glucose-6-phosphatase.
(two) pathogenesis
Glucose-6-phosphatase is present in the liver and kidney mucosa of the human body. This enzyme can promote the decomposition of glucose 6-phosphate into glucose and phosphoric acid. When the enzyme is deficient, the liver cannot decompose glycogen, lactic acid and amino acids into glucose, resulting in low fasting. Blood sugar, the result of a large amount of fat mobilization, triglyceride in the liver, resulting in increased triglyceride in the blood, and even fatty liver, and due to fatty acid in the liver oxidative insufficiency, blood lactic acid increased, blood lactic acid can not be retrograde Glycogen-induced increase in lactic acid in the blood, and increased metabolism of sugar bypass, increased uric acid synthesis, and increased uric acid in the blood, because starch-1,6-glucosidase can still break down glycogen to release glucose, so glycogen The heterogeneous effect is also stronger.
Classification of glycogen storage diseases:
Defective type 1.0 urinary diphosphate glucose-glycotransferase, clinical manifestations of hepatomegaly, hypoglycemia, congenital muscle weakness, decreased muscle tone.
2. Type I glucose-6-phosphonate deficiency, clinical manifestations of hepatomegaly, hypoglycemia, ketotoxicity, acidosis.
3. Type II -1,4-glycosidase deficiency, heart enlargement, heart failure, giant tongue, muscle weakness.
4. Type III polysaccharide-1,6-glucosidase and/or fructose-1,41,4-transglucosidase deficiency, clinical manifestations of hepatomegaly, hypoglycemia, congenital muscle weakness, decreased muscle tone.
5. Type IV polysaccharide-1,41,6-transglucosidase deficiency, clinical manifestations of liver, splenomegaly, cirrhosis.
6. V-type muscle phosphorylase deficiency, clinical manifestations of muscle pain after exercise, weakness.
7. VI type liver phosphorylase deficiency, clinical manifestations of hepatomegaly, hypoglycemia.
8. Type VII phosphofructokinase deficiency, clinical manifestations of muscle pain after exercise, weakness.
9. VIII type hexose phosphate isomerase deficiency, clinical manifestations of muscle pain after exercise, weakness.
10. IXa type phosphorylase kinase deficiency, clinical manifestations of hepatomegaly, hypoglycemia.
11. IXb type phosphorylase kinase deficiency.
12. X-type phosphorylase kinase deficiency, clinical manifestations of muscle pain after exercise, weakness.
Prevention
Glycogen storage disease type I prevention
Difficulties in the treatment of genetic diseases, unsatisfactory results, prevention is more important, preventive measures include avoiding close relatives marriage, implementation of genetic counseling, carrier genetic testing and prenatal diagnosis and selective abortion to prevent the birth of children.
Complication
Glycogen storage disease type I complications Complications
Infection is the most common serious complication.
Symptom
Glycogen storage disease type I symptoms Common symptoms Weight loss fatigue ketoacidosis fatigue liver enlargement gum bleeding weakness hyperuricemia blood glucose elevation dyslipidemia
The disease is autosomal recessive, both men and women can be ill, infants are more common, with different age, symptoms are slightly different, muscle weakness and mental decline is the main manifestation of the nervous system.
1. Liver and kidney enlargement of liver and kidney enlargement is not obvious, and it is not noticed. The liver is swollen gradually around 1 year old, and even occupy the entire abdominal cavity. The kidney is also swollen, but the kidney function is normal.
2. Hypoglycemic infants can develop hypoglycemic convulsions, coma and mental decline, and severe patients with ketoacidosis.
3. Growth retardation is short or thin, and some patients are obese. The reason is that 6-phosphate glucose can not be decomposed into glucose to synthesize glycogen. At the same time, gluconeogenesis enhances liver glycogen storage too much, and free glucose cannot be synthesized. Glycogen is converted into fat.
4. It is easy to fatigue and the limbs are weak. The lower limbs are heavy and the severe ones are difficult to walk.
5. Hemorrhage of nasopharynx and gums is common. The cause is related to platelet dysfunction. It may also be related to the lack of glucose-6-phosphatase in platelets, or indirectly due to the lack of this enzyme in the liver.
6. Hyperuricemia and gout are more common in children under 10 years of age, due to increased production of uric acid, lactic acid and pyruvic acid, which affects the elimination of uric acid.
7. Hyperlipidemia is caused by long-term hypoglycemia, which shows triacylglycerol, cholesterol, lipoprotein increase, and yellow tumor in the buttocks and extremities.
Examine
Examination of glycogen storage disease type I
1. The patient has a low fasting blood glucose and a specific increase in the fructose tolerance test and the galactose tolerance test.
2. Triacylglycerol, cholesterol, fatty acids and uric acid are significantly increased.
3. Liver biopsy showed an increase in hepatocytes and an increase in glycogen; glucose-6-phosphate active enzyme decreased or disappeared.
4. Muscle biopsy The glycogen content is slightly increased, the glycogen structure is normal, and the glucose-6-phosphate active enzyme in platelets can also be reduced or disappeared.
Diagnosis
Diagnosis of type I glycogen storage disease
More common in infants, fasting blood sugar is very low, combined with hyperlipidemia, hyperuricemia and clinical examination of hepatic and renal enlargement, can be diagnosed, the diagnosis of this disease can be used for adrenaline test, the method is as follows: intramuscular injection 1: 1000 adrenaline 0.03ml/kg, 30 minutes before injection and 30, 60, 90, 120, 150min after blood intake blood glucose measurement, normal human injection of adrenaline 1h, fasting blood glucose increased by 1.65 ~ 2.48mmol / L, 2h returned to The original level.
It can also be diagnosed as a highly specific fructose or galactose tolerance test by intravenous injection of fructose (0.5g/kg body weight) or galactose (1g/kg) in 25% solution, 1h before and after injection. Inside, blood is taken every 10 minutes to determine the content of glucose, lactic acid, galactose, and fructose. If glucose is normal and lactic acid is elevated, it can be diagnosed.
Pay attention to the identification of other types of glycogen storage disease, diabetes, gout, liver disease, metabolic syndrome (X syndrome).
