Galactosemia

Galactosemia: an inherited disease associated with impaired galactose metabolism

Galactosemia is a hereditary disease that occurs due to disturbances in the metabolism of galactose. Galactose, which enters the body with food as part of lactose (milk sugar), is not converted into glucose due to a hereditary defect in the key enzyme - galactose phosphate uridyl transferase. This leads to the accumulation of galactose and galactose phosphate in the blood and tissues, which has a toxic effect on the central nervous system, liver, eye lenses and other organs.

The mode of inheritance of galactosemia is autosomal recessive, that is, the disease manifests itself only in those people who have two copies of the mutated gene, one received from the mother and the other from the father. In such people, galactose phosphate uridyl transferase activity is reduced or undetectable.

The clinical picture of galactosemia can vary from a severe form with severe neurological symptoms, jaundice, liver enlargement and retardation in physical and neuropsychic development to the Duarte form, which is asymptomatic, but increases the susceptibility to chronic liver diseases.

To diagnose galactosemia, special laboratory tests are used, including determining the level of galactose in the blood and urine, as well as the activity of galactose phosphate uridyl transferase in red blood cells. To confirm the diagnosis, special examinations of the child are carried out.

Treatment of galactosemia involves transferring the child to a special dietary regimen that excludes milk and products containing lactose. For this purpose, special lactose-free milk formulas have been developed. Symptomatic therapy is also carried out, including detoxification and rehydration measures.

In conclusion, galactosemia is a rare inherited disease that can lead to serious complications. Early diagnosis and timely treatment can improve the quality of life of patients with galactosemia.

Galactosemia (Latin galactosemia - lactic acid + Greek σπίθα ἡ σάρκος "icholia" from ancient Greek ὁ νεφρός ὑμνή "kidney", i.e. the kidney that produces urine [2], less often μ ωτᾱλ λώσα “urine” [3], [4]) is a group of hereditary metabolic disorders caused by a deficiency or excess of the enzyme galactokinase. The name of the disease is due to the fact that clinical manifestations can include both manifestations of the gastrointestinal tract with excessive entry of galactose and/or galactose-1-phosphate into the blood, and various defects of the nervous system due to enzyme deficiency. But galactosidase deficiency occurs. Both variants of the pathology are called galactosemia [5].

Galactosemia or galactozouria is also called galactogenic diabetes mellitus and genetic hemolytic anemia, although neither one nor the other is related to it. Galactose is present in milk and dairy products such as whole milk, cheese, butter and yogurt, but not in cottage cheese. Galactosuria is a fairly rare genetic disease that manifests itself in galactose intolerance. Scientists believe that galactosemia is characterized by genetic defects in protein structures encoded by galactokinases. These structures catalyze reactions that convert galactose to galacto-1-phosphate. If any of them is damaged, even a small part of the glucose supply, which is necessary for important metabolic processes, becomes unavailable to the body. The development of neonatal galactosemic galactose diabetes depends on a defect in the GALTL gene on chromosome 8, usually caused by recessive inheritance. Patients with these mutations typically transport galactose normally across intestinal cell membranes and absorb it into the body, even though they do not produce enough of the enzyme galactosidase, which helps the body convert most galactose from food into glucose. While in adults who grow up without sufficient levels of digested galactose, there is a deficiency of phosphogalactokinase and the level of this sugar remains high. This is indicated by a decrease in hemoglobin levels and the development of hemolytic manifestations leading to recurrent acute galactosemic hypoglycemia in some young children born to mothers without a history of celiac disease or an autosomal recessive or apparently silent phosphogalactosidase deficiency. These patients may often be at risk of developing hemolytic anemia.