Diagnosis of glycogenases
Last reviewed: 23.04.2024
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Glycogenosis type I
The main methods for confirming the diagnosis are biochemical (determination of the activity of the enzyme glucose-6-phosphatase in liver biopsy) and molecular genetic (detection of mutations in the genes G6PC and G6PT). Glycogenosis type 1a is more common, so diagnosis begins with the exclusion of this form of the disease, but if neutropenia is observed in patients, the G6PT gene is first examined .
In the general blood test, thrombocytopenia, normocytic anemia, neutropenia (type I glycogenesis), in biochemical blood analysis: metabolic acidosis, glucose reduction, increased lactate concentration (5-10 mM) and uric acid, increased lipid content (mainly triglycerides, cholesterol , phospholipids, very low density lipoproteins, low density lipoproteins [LDL]), increased activity of alkaline phosphatase, 8-glutamyltransferase. In the general analysis of urine - proteinuria. Liver biopsy: a decrease in the activity of glucose-6-phosphatase, an increase in the amount of glycogen (3 times or more). Ultrasound of the abdominal cavity: an increase in the size of the liver, kidneys, spleen. Morphological examination of the liver reveals increased hepatocytes with the deposition of glycogen and fats, with morphological examination of the kidneys - focal segmental glomerulosclerosis and interstitial fibrosis.
Glikogenov type III
The diagnosis is confirmed by determining the enzyme activity in leukocytes, erythrocytes or fibroblasts or by DNA analysis methods. It is possible to carry out prenatal diagnostics in families with burdened heredity.
Liver biopsy, muscle: decreased activity of amylo-1,6-glucosidase, increased glycogen content (4-fold and more).
Biochemical blood test: increase in uric acid concentration, increase in activity of creatine phosphokinase, alanine aminotransferase, aspartate aminotransferase, decrease in glucose concentration, increase in cholesterol concentration, triglycerides.
Glycogenosis type IV
The main methods for confirming the diagnosis of glycogenosis IV are molecular-genetic. It is possible to carry out prenatal diagnostics in families with burdened heredity.
In liver biopsy - accumulation of glycogen of a changed structure.
Biochemical blood test: increased activity of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase.
Glycogenosis of type VI
The main methods for confirming the diagnosis are molecular genetic: the detection of mutations in the PYGL gene . Prenatal diagnosis in families with burdened heredity is possible, but ethically questionable in connection with a benign course.
Glycogenosis IX type
Exact diagnosis of this disease is carried out by molecular genetic methods. Prenatal diagnosis is possible, but in connection with the benign course of the disease is ethically questionable.
Glycogenosis of type 0
Patients with type 0 glycogenosis can be observed for a long time by endocrinologists, especially when they have glucosuria and ketonuria. The diagnosis is confirmed with a liver biopsy - a decrease in glycogen content and deficiency of the glycogen synthase enzyme. It is possible to conduct DNA diagnostics.
Glycogenosis type II
The main method of confirming the diagnosis is to determine the activity of a-glycosidase in a culture of skin fibroblasts or a muscle biopsy. It is also possible to conduct DNA diagnostics.
In the biopsy of the bone marrow - "foam cells"; deposition of glycogen in muscles and hepatocytes.
It is possible to carry out prenatal diagnostics in families with burdened heredity.
Glycogenosis of type V
To confirm the diagnosis, determine the ammonium, lactate and CKK against the background of the ischemic test. In the study of muscle biopsy, subsarcolemal accumulations of glycogen are detected. The main method of confirming the diagnosis is the detection of mutations in the gene of myophosphorylase. It is possible to carry out prenatal diagnostics in families with burdened heredity.
Glycogenosis type VII
Muscular biopsy reveals subaracho- lemal clusters of normal glycogen in its structure. The main method of confirming the diagnosis is DNA diagnostics.
Instrumental methods
Glycogenosis type III
Electromyography reveals signs of primary muscle damage. With Echocardiography, there are signs of cardiomyopathy.
Glycogenosis type IV
Ultrasound of the abdominal cavity reveals an increase in liver size.
Differential diagnostics
Glycogenosis type I
Differential diagnostics is performed with other hepatic forms of glycogenosis: types III, IV, VI and other hereditary metabolic diseases accompanied by hepatomegaly: insufficiency of al-antitrypsin, defects in beta oxidation of fatty acids; mutations of the mitochondrial genome (manifestation in the form of liver failure).
Glycogenosis type III
Differential diagnosis should be carried out with other glycogenases, mainly with types 1a, V, VI, as well as with hereditary metabolic diseases characterized by muscle hypotension, lactic acidosis and hepatomegaly (defects in beta oxidation of fatty acids, mitochondrial diseases).
Glycogenosis type IV
Differential diagnostics: hepatitis of different etiology, glycogenoses of types 1a, III, VI. Other hereditary metabolic diseases, characterized by cirrhosis of the liver: a1-antitrypsin deficiency, mitochondrial genome mutations, manifesting as hepatic insufficiency, tyrosinemia, type 1a.
Glycogenosis type II
Differential diagnosis of Pompe disease should be carried out with muscular dystrophy, polymyositis, spinal muscle atrophy, skapuloperoneal syndromes and Danone's disease.
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