What is Type X Glycogenosis?
Type X glycogenosis is a hereditary disease that is caused by a lack of enzymes involved in glycogen metabolism; characterized by a violation of the structure of glycogen, insufficient or excessive accumulation of it in various organs and tissues.
Causes of Type X Glycogenosis
A case is known in a single patient; inheritance has not been established.
Pathogenesis during Type X Glycogenosis
An enzyme defect is found in the liver and muscles.
Symptoms of Type X Glycogenosis
Hepatomegaly was observed, 6 years after the onset of the disease, muscle pains and muscle cramps appeared after exercise.
Diagnosis of Type X Glycogenosis
To confirm the diagnosis of glycogenosis and establish its type in the hospital, a biopsy of the liver, muscles (sometimes skin) is performed, followed by histochemical examination; in this case, the glycogen content in the tissues and the activity of the enzymes involved in its metabolism are determined. In case of type II glycogenosis, the activity of acidic α-1,4-glucosidase in the blood cells as well as in the fibroblast cell culture of the patient’s skin and muscles is also determined. Type II glycogenosis can be diagnosed prenatally by biochemical examination of cells of desquamating epithelium of the fetal skin located in the amniotic fluid obtained by amniocentesis.
Differential diagnosis in newborns is carried out with syphilis, toxoplasmosis, cytomegalovirus infection, liver diseases, at an older age – with Gaucher disease, Nimann-Peak disease, myatonia, xanthomatosis. Neuromuscular disorders can mimic progressive muscular dystrophy, amyotrophy – Sharko-Marie-Tooth neural amyotrophy and Verdnig-Hoffmann spinal amyotrophy (with a generalized form of type II glycogenosis); crucial in the diagnosis are relevant biochemical, electrophysiological and morphological studies of muscles.
Treatment for Type X Glycogenosis
The treatment is aimed at combating metabolic disorders, including with acidosis. In some cases, the use of glucagon, anabolic hormones and glucocorticoids is effective. Frequent meals high in easily digestible carbohydrates are essential for hypoglycemia. With muscle forms of glycogenosis, improvement is observed when following a diet with a high protein content, the appointment of fructose (inside 50-100 g per day), multivitamins, ATP. Attempts are being made to introduce missing enzymes to patients.
Patients with glycogenosis are subject to clinical observation by a doctor of the medical-genetic center and a pediatrician (therapist) of the clinic.
Prevention of Type X Glycogenosis
Prevention is not developed. To prevent the birth of a child with glycogenosis in families where there were similar patients, medical and genetic counseling is carried out.