Galactosemia

Galactosemia is a hereditary disease, which is based on the metabolic block in the way of galactose transformation into glucose.

Etiology, pathogenesis. Galactose, supplied with food in the composition of lactose-milk sugar, undergoes phosphorylation, with the formation of galactose-1-phosphate; Further its transformation in the disease does not occur in connection with the hereditary defect of the key enzyme-galactose-1-phosphate-uridyltransferase. Galactose and galactose-1-phosphate accumulate in the blood and tissues, having a toxic effect on the central nervous system, the liver, and the lens of the eye, which determines the clinical manifestations of the disease. The type of inheritance of galactosemia is autosomal recessive.

Clinical picture. The disease manifests itself in the first days and weeks of life with severe jaundice, liver enlargement, neurologic symptoms (seizures, nystagmus, muscle hypotension), vomiting; In the future, there is a lag in physical and neuropsychic development, cataracts occur. The severity of the disease can vary significantly; Sometimes the only manifestation of galactosomia are cataracts or intolerance to milk. One of the variants of the disease - the Duarte form - is asymptomatic, although the tendency of such individuals to chronic liver diseases is noted.

At laboratory research in a blood the galactose which contents can reach 0,8 g / l is defined; Special methods (chromatography) can detect galactose in the urine. The activity of galactose-1-phosphate-uridyltransferase in erythrocytes is sharply reduced or not determined, the content of galactose-1-phosphate is increased 10-20 times compared to the norm. In the presence of jaundice, the content of both direct (diglucuronide) and indirect (free) bilirubin increases. Other biochemical signs of liver damage are also characteristic (hypoproteinemia, hypoalbuminemia, positive samples for violation of colloid resistance of proteins). Significantly reduced resistance to infection.

Diagnosis. Positive tests for sugar and the detection of galactose in the urine in the first days of life, as well as its blood level of more than 0.2 g / l require a special examination of the child for galactosemia. There are special fluorometric, spectrophotometric and radiometric methods for determining the activity of galactose-1-phosphate-uridil-transferase, which are performed in centralized biochemical laboratories.

Differential diagnosis is usually performed with diabetes mellitus. Treatment. When confirming the diagnosis, the child needs to be transferred to food, with the exception of mainly women's milk. For this purpose, special products have been developed: soya-bean, nutramigen, lactose-free epithelium. Recommended replacement blood transfusions, fractional blood transfusion, infusion of plasma. From medicines, the purpose of potassium orotate, ATP, cocarboxylase, vitamin complex is shown.

Forecast. Heavy forms end lethal in the first months of life, with prolonged flow, the phenomena of chronic liver failure or CNS lesions may appear to the fore.

Prevention. The high efficiency of early detection of pregnant women in high-risk families and antenatal prevention, consisting in the exclusion of milk from the diet of pregnant women, is shown. The registration of risk families allows early, that is, even in the preclinical stage, to undergo a special examination of the newborn and, with positive results, transfer it to lactose-free feeding. For early detection, special screening programs for mass screening of newborns have also been proposed.