Classification of primary ( hereditary and congenital ) violation of intestinal absorption ( and . In . Frolkis )

August 12, 2017 17:51 | Genetic Diseases

I. Primary malabsorption monosaccharides.

1. Primary malabsorption of glucose and galactose.

2. Primary fructose malabsorption.

II.Primary disorders of amino acids intake.

1. Hartnapa disease (1: 26 000-1: 200 000).

2. Cystinuria (1: 7000 births).

3. Congenital lizinuriya (1: 60 000 - 80 000 thousand.).

4. Primary malabsorption of tryptophan.

5. imino glitsinuriya (1:15 000).

6. Syndrome Loy.

7. Primary malabsorption methionine.

III.Primary malabsorption of fats.

1. A betalipoproteinemiya.

2. Primary bile acid malabsorption.

IV.Primary malabsorption of vitamins.

1. Primary malabsorption of vitamin B12.

2. Primary folate malabsorption.

V. Primary malabsorption of minerals.

1. Acrodermatitis enteropathic.

2. Primary hypomagnesemia.

3. Menkes syndrome (1: 35 000).

4. Family hypophosphatemic rickets.

5. Idiopathic primary hemochromatosis.

Hereditary malabsorption of amino acids necessary to distinguish with hereditary disorders of amino acid metabolism, in which the transport

processes in the intestine are not affected.The study inborn errors of amino acid transport in the small intestine revealed that it is quite a variety of disorders.On the one hand, they can be lightweight and not accompanied by clinical symptoms, on the other hand, can occur quite severe, sometimes fatal disorders (Lowe syndrome, congenital lizinuriya).There is strong reason to believe that under these pathological conditions, there are genetically programmed defect in the synthesis of the respective carriers.

can assume the existence of 4 transport systems and, consequently, the corresponding vectors:

1) for absorption of neutral amino acids (most amino acids);

2) for the absorption of basic amino acids (arginine, lysine, ornithine, cystine);

3) for the transport of acidic amino acids (aspartic, glutamic);

4) for sucking the proline amino acids, hydroxyproline Sarazin, and glycine betaine.One can not exclude independent system for absorption of methionine.Apparently, there is also a separate mechanism for transport of amino acids comprising the peptides, thereby compensate for some genetic defect diseases.

great importance is the fact that the primary pathology absorption of amino acids in most cases there is a defect in the transport of these substances kidneys.At the same time there is increased loss of certain amino acids in the urine.

For most hereditary defects absorptive small intestine function abnormal gene is localized to one or another of the 22 autosomes.In some pathological conditions (syndrome Menkes, family gipofos-fatemicheskom rickets) abnormal gene is localized in the sexual X chromosome, t. E. There is a sex-linked anomaly, with malabsorption clinically manifested mainly in males and in females- only in cases when an abnormal gene is present in both the X-chromosome.

majority of hereditary disorders of intestinal absorption of inherited recessive type.This inheritance suggests that the clinical manifestations of the disease and expressed biochemical changes occur in individuals who are homozygous for this abnormal gene.Heterozygotes with only one abnormal gene from the pair and one normal gene, usually almost healthy, although they have latent (hidden) biochemical changes can be observed.Among parents of such children are more likely than in the population, there are consanguineous marriages.

primary reason for violations of absorptive function of the small intestine are genetically determined disorders of the molecular mechanisms of intestinal transport of nutrients.Changes in the structure of the small intestine mucosa observed in some forms of such violations (Loy syndrome, fatal familial protracted diarrhea, abetalipoproteinemia, enteropathic acrodermatitis), develop secondary to already existing disorders.

presence of selective (election) disorders of intestinal absorption is an important confirmation of the existence of independent transport systems for individual substances (glucose, galactose, fructose, and various amino acids, fats, bile acids, vitamin B12, zinc, magnesium, copper, phosphates, electrolytes).The existence of the common transport mechanisms in the kidney and intestine show not only selective absorption amino disorder, but other forms of primary malabsorption (glucose and galactose malabsorption, hypophosphatemic rickets), occur where transport disturbances in the small intestine and in the kidneys.

indispensable for human food items now believe chromium, copper, cobalt, manganese, molybdenum, selenium and zinc.It is known that the physiological role of the overall trace elements is determined by their connection to the enzyme systems in the cell.Trace elements provide stability of spatial structure of the protein molecules in the body, which gives it greater vitality and reactivity.Metals are part of enzymes and their complexes.Thus, minerals are essential for the synthesis of all proteins in the human body.