Hereditary kidney disease
Currently, hereditary and congenital kidney diseases are one of the most important causes of disability of children and adults. More than 70% of all cases of chronic renal failure are due to precisely these diseases. More than 50% of children and 15% of adults are admitted to substitution therapy for hemodialysis centers in connection with hereditary diseases of the kidneys .
Long-held beliefs about the incurability of hereditary and congenital kidney diseases are changing in recent years. This applies primarily to congenital uropathies, correction of which became possible due to the success of pediatric surgery. No less important are the possibilities of diagnosing hereditary diseases of the kidneys in the early childhood period, namely in the first month of the child's life. The technology of recognition of polycystic disease is already entering the position of wide practical application. Effective kidney transplantation is performed for children with Finnish type of congenital nephrotic syndrome. At the same time, there are reports of full functional rehabilitation of children who reached the age of four years or more after transplant.
Hereditary nephropathy is a term used mainly in relation to kidney disease, inherited monogeneously, where the only cause of the development of pathology is a gene mutation. Their incidence among kidney diseases is about 9%.
Hereditary defects can appear at various levels of the nephron, which is the main structural unit of the structure of the renal tissue. Hereditary glomerulopathies are the primary lesion of the kidneys, in which the glomerular apparatus is primarily affected. The classic manifestation of glomerulopathies is hereditary nephritis, as well as Alport syndrome. The primary damage to the kidneys with the primary damage to the tubules is most often caused by a disruption in the functions of the enzyme systems located in this part of the kidneys, as well as the violation of the tubular transport of various metabolic products, which leads to the development of pathological processes and conditions designated as tubulopathies.
The term "family nephropathy" is used in the presence of the same type of kidney disease in several members of the same family, most often these diseases are genetically determined. However, this does not exclude family acquired diseases, when they are associated with the influence of homogeneous environmental factors on the family( unfavorable living conditions, the defeat of several family members by pathogenic bacteria - streptococcus).But in these cases, the probability of formation of renal diseases is determined for the most part by the presence of hereditary predisposition.
Congenital means kidney disease, the signs of which are found in the period of newborn. However, a large number of congenital malformations can occur many years after birth. Special methods of investigation have been able to reveal in the antenatal period various types of disturbance of normal kidney development. Congenital diseases are associated with hereditary or teratogenic( unfavorably affecting the fetus in the prenatal period) factors, acting, as a rule, against the background of the existing genetic predisposition. Not all hereditary diseases of the kidneys are considered as congenital, which is associated not only with the late appearance of symptoms characteristic of them. This applies primarily to such forms of diseases that are formed with a strong or dominant( predominant) effect of adverse environmental factors. Polygenically inherited pathology is revealed in the process of human growth and development, although gene mutations, as well as the resulting deficiency of enzymes or structural proteins, already exist at the stages of intrauterine development of the child. A special group consists of multifactorial diseases of the kidneys, which are caused by the action of viruses, bacteria, protozoa. Also, toxic and drug nephropathies are shown separately, which are manifested in people who have corresponding genetic disorders or abnormalities of the immune system.
A special group of nephro- and uropathies are diseases associated with chromosomal pathology.
Chromosomal diseases or syndromes include diseases caused by genomic or structural disorders. They are not hereditary, although they relate to genetically determined pathology. Chromosomal diseases are characterized, as a rule, by multiple malformations of various organs. The frequency of lesions of the kidneys and urinary organs with a number of chromosomal diseases can be quite high( in particular, with trisomy chromosomes).With trisomy of chromosome 21, loss of part of the long arm of chromosome 18, the frequency of malformations of the organs of the urinary system exceeds the frequency of similar anomalies in the urinary system in the population.
As a rule, changes in the kidneys and urinary tract are not the leading symptoms of chromosomal disease, and they are not the cause of the unfavorable outcome of the disease, although there are exceptions.
In recent years, due to the introduction of new research methods in clinical genetics that allow to determine a mutation at the DNA level, it is obviously possible to detect the smallest chromosomal anomalies that can not be determined by the old diagnostic methods. It can be expected that new methods will help to clarify the causes of anatomical and structural anomalies of various organs, including kidneys. However, even at the present time, several dozen chromosomal syndromes should be oriented, in which there are various abnormalities in the structure of the kidneys and urinary organs.
All hereditary pathologies from the kidneys can be divided into several large groups. The first group combines severe anatomical abnormalities, such as congenital absence of the kidney, horseshoe-shaped kidney or other anatomical abnormality of the urinary system. More often we are talking about congenital urological defects. The second group consists of diseases associated with structural changes in the kidney tissue. Most of them are based on a cystic transformation of the kidney tissue. The third group of hereditary kidney diseases occurs with pathology, which, slowly developing, leads to renal failure. The fourth group unites the metabolic pathology, in which the leading is a violation of the functional capacity of the kidneys, while the anatomical and structural changes in the kidney tissue are minimal.