Insufficient intestinal disaccharidases

August 12, 2017 17:50 | Symptoms Of Disease

Hereditary defects in bowel disaccharidases system manifest persistent gastrointestinal disorders and dystrophy, which is caused by a violation of digestion and absorption of disaccharides in the intestinal mucosa.In 1958, P. Durand found in the child malnutrition with a low activity of the enzyme that breaks down milk sugar, while determined a significant amount of lactose in the urine of the patient.We should talk about the autosomal dominant type of inheritance.

lactase deficiency is more common other forms disaccharidase deficiency, therefore attracting the most attention, since milk and dairy products are major in nutrition of many nations, especially in childhood.If lactase deficiency is relatively rare (2-30%) in Europe, in some parts of Africa and Asia - more than 90% of the total population.only a few population-based studies of the spread of disease carried out in our country.

Already in the first reports about ethnic differences in the frequency of lactase deficiency occur assumptions abou

t the genetic nature of this type of pathology, according to which the ability of lactose digestion in adults is considered an innate property that is inherited.The ability to break down lactose (milk sugar) is transmitted in an autosomal dominant manner with high frequency of manifestation of the mutant gene, and the primary lactase deficiency - in an autosomal recessive manner.There is the so-called geographical variant of the genetic hypothesis, the essence of which is as follows.It is assumed that in the Paleolithic era in humans as in other mammals, after the end of feeding activity of lactase in the intestine significantly decreased or disappeared entirely, but in some individuals lactase activity remained all his life.When there was dairy cattle and were dairy products, lactose absorbers become prevalent in certain geographical areas, where the population was fed with milk and its products.Special calculations show that since the beginning of the use of milk enough time has passed that there was an appropriate selection.For example, in Finland, where the milk consume about 3,000 years, lactase deficiency occurs in 17% of the population.The inhabitants of the northern regions of Finland the Lapps use milk just 150-300 years, and they detection of this disease is 34%.Of course, one can hardly agree with the fact that only the activity of lactase in the intestine may be the leading factor in the selection.Apparently, contributed to the survival of resistance to infections and other genetic characteristics.The ability of splitting lactase, obviously, should be considered as a component of multi-factor selection process.

been suggested the existence of other genetic mechanisms of lactase deficiency.Congenital deficiency of the enzyme that breaks down milk sugar explain gene mutation responsible for the synthesis of lactase, whereby the enzyme is either not synthesized or formed by its inactive form.In adults lactase deficiency is assumed gene mutation, resulting in a structurally normal enzyme, but the process is very slow, what is the reason, perhaps, hormonal disturbances.This view considers lactase deficiency as a mutation, a defect in certain genes, and ability to break down lactase - like species of human ability.In addition to the genetic theory of lactase deficiency, received, despite some shortcomings, the universal recognition, expressed the hypothesis, considering the disease as a result of intestinal diseases, as well as the assumption that the enzyme deficiency is the result of the braking effect of certain foods on the activity of lactase in the intestinal mucosa.In humans, eating milk, the level of the enzyme in the intestinal mucosa is high, and among people who use it in small quantities or not at all eats dairy products, common deficiency.However, all attempts to cause an increased number of researchers lactase (the enzyme) using lactose or milk food were unsuccessful.

Saharazno-izomaltaznaya failure - a variant of hereditary intolerance to disaccharides, due to decreased activity of enzymes such as maltase and isomaltase, as well as lack of intestinal mucosa invertase enzyme.It revealed the genetic nature of the disease.Some authors speak of autosomal dominant inheritance, while others argue that the inheritance of sucrase deficiency is an autosomal recessive, especially in cases of blood marriages.Homozygous individuals for life remain an intolerance sucrose and heterozygous enzyme deficiency may be asymptomatic, or saharaznaya failure occurs only in childhood.Boys and girls suffer equally often.

case of insufficient enzymes such as sucrase, isomaltase and maltase, are quite rare.There is a birth defect of the enzyme sucrase, whereby sucrose is not split into glucose and fructose.Maltase and isomaltase deficiency is usually combined with other disaccharidases deficit.In severe intolerance to starch but maltase and isomaltase deficiency, should bear in mind the chronic pancreatic insufficiency, as well as an extremely rare condition congenital absence of pancreatic amylase.With maltasie and izomaltaznym deficit can be combined lactase deficiency, especially acquired.Combined saharazny, izomaltazny and maltasie deficiency occurs much more frequently.Loss of function of several enzymes is the result of a single mutation or multifunctional missing enzyme, which explains the combination of metabolic defects, and some splitting of disaccharides.It is believed that the structural gene controlling the synthesis of several enzymes damaged under the influence of exposure to toxic or infectious, or one and the same factor, toxic or infectious, disables multiple enzymes.