Hereditary nephritis( better known as Alport syndrome) - pathology is rare. According to official data, in Russia, 100,000 newborn babies have 17 with such an anomaly of development. In Europe, 1% of all patients with chronic renal failure( CRF) are precisely people with hereditary nephritis. And 2.3% of kidney transplants are done by patients with this diagnosis.
Alport Syndrome?
Hereditary nephritis is a constantly progressing kidney disease, which often goes hand in hand with hearing loss and serious vision problems. In the reference books, one can find the definition of Alport syndrome( SA) as an unimmunized hereditary form of glomerulopathy, that is, defeat of the glomerular apparatus of the kidneys.
The fourth collagenous variety forms the basis of the basal membranes of the renal glomeruli, the cochlear apparatus( part of the inner ear), and the capsules of the lens. Hence - and the simultaneous disruption of the kidneys, hearing and vision.
International Classification of Diseases of the 10th Revision( ICD-10) - the main normative document that systematizes all existing health disorders, - classifies children's illness as a class of congenital anomalies, deformations and chromosomal abnormalities. Since the CA suffers from a number of organs, the disease is included in the group of congenital malformations affecting several systems at once. And it is marked with the code Q87.8 - these are "other specified syndromes of congenital anomalies, not classified elsewhere".
Reasons for
The main and only reason children are born with Alport syndrome is a genetic mutation. One of the three genes - COL4A5, COL4A4, COL4A3 - is damaged. The COL4A5 gene is located on the X chromosome and encodes the collagen chain of the a5-chain."Place of residence" of the genes COL4A3 and COL4A4 - the 2nd chromosome. They, accordingly, store information about collagen chains a3- and a4-.
Most often the damaged gene is passed on to the baby from the parents. When the kidney disease passes over the X chromosome, the mother can become an anomaly transmitter to both her son and daughter. The father is only a daughter. The likelihood that a baby will be born with a kidney damage, increases at times if there are people with urinary system diseases( primarily CRF) in the family.
But in 20% of cases, children with Alport syndrome are born in families where all relatives have perfectly healthy kidneys. Here we are talking about random, spontaneous genetic mutations.
Symptoms of
Congenital hereditary nephritis develops with a deficiency of collagen, one of the main structural elements of connective tissue. As a result of the collagen deficiency, the basal membranes of the renal glomeruli, inner ear and eye apparatus become thinner and split, and the organs themselves cease to fully cope with their function.
All symptoms of Alport syndrome are divided into two groups - renal and extrarenal manifestations. Among the kidneys, two main signs are diagnosed: hematuria( traces of blood in the urine) and proteinuria( proteins in the urine).Often they are united under the name "isolated urinary syndrome".
Isolated urinary syndrome in children can be seen not immediately. Visible signals appear only in the 3-5th year of life, and sometimes in 7-10 years. But the smallest droplets of blood in the urine are always present, even if at first they are not visible - this is an asymptomatic microhematuria. Therefore, hematuria is considered the main specific symptom of Alport syndrome.
The extrarenal symptoms of congenital nephritis appear later. These are:
- hearing loss( at first the child ceases to distinguish high sounds, then ordinary speech);
- various eye disorders;
- lag in physical development;
- congenital anomalies( deformed ears, high palate, jointed or additional fingers - no more than 7 signs);
- is rare - a leiomyomatosis( proliferation of smooth muscle fibers) of the esophagus, trachea, bronchi.
As the disease progresses, classical signs of renal failure appear: yellowish and dry skin, dry mouth, decrease in the amount of urine, etc. Increased pressure in the renal vessels - hypertension.
Classification of
There are two classifications of the Alport syndrome in children. The first is a genetic, anomaly-like type of inheritance.
According to this classification, three types of congenital nephritis are distinguished:
- X-linked dominant, or classical( about 80% of all patients with CA);
- is autosomal recessive( 15% of children with congenital anomaly);
- is autosomal dominant( the rarest type, about 5% of patients).
The second, basic classification names three variants of kidney disease:
- Jade, accompanied by hematuria, hearing loss and vision problems( eye lesions).This is the X-dominant type of congenital malformation.
- Jade with hematuria, but without sensory lesions. Corresponds to autosomal recessive form. Benign family hematuria.
The first two options are a progressive renal disease, the inevitable outcome of which is chronic renal failure. With benign family hematuria, chronic renal failure does not develop, and quality and life expectancy do not suffer.
Diagnosis
According to clinical guidelines for the diagnosis of Alport syndrome in children, the likelihood of congenital nephritis is high if three of the five symptoms are present.
These attributes include:
- The family has cases of hematuria, in the genus there were cases of death from chronic renal failure.
- In the family, the child has been diagnosed with hematuria and / or proteinuria.
- Specific changes in the patient's basement membrane of the renal glomeruli( by biopsy results).
- Congenital vision pathology.
- Hearing loss( identified by audiometry data).
If you suspect a syndrome of Alport use a number of traditional diagnostic methods:
- anamnesis( information about the presence of the same symptoms and deaths from CRF in blood relatives);
- physical methods( palpation, tapping);
- laboratory tests( clinical analysis of urine, etc.);
- ultrasound and kidney biopsy.
Specialists also recommend a DNA test for family members of a young patient using DNA probes. This allows us to determine the carrier of the mutant gene. In addition, it is possible to use DNA probes for prenatal diagnosis of Alport syndrome, even during mother's pregnancy. This is especially important if a boy is waiting for a family - for men, the CA is more difficult.
Differential diagnostics is mandatory: for delimiting congenital nephritis from nephropathy and acquired glomerulonephritis.
Treatment of
At the initial stage of congenital nephritis powerful complex therapy is not required.
The following therapeutic measures for children are required in the setting of a renal diagnosis:
- no serious physical exertion( exemption from physical education lessons);
- regular walks;
- balanced nutrition;
- phytotherapy with the appearance of blood in the children's urine( infusion of nettle and yarrow, juice of chokeberry);
- vitamins A and E, B6( pyridoxine) to improve metabolism( courses of 2 weeks);
- for the same purposes - injections of cocarboxylase.
Boys to reduce proteinuria are recommended ATP( angiotensin converting enzyme) inhibitors and angiotensin receptor blockers.
Forecast
The prognosis for Alport syndrome depends on two factors: the variant of the disease and the sex of the child. The fastest progression is the classic, X-dominant form of Alport syndrome in boys.
In this case, CRF is diagnosed in all patients up to 60 years, and in 50% - up to 25 years. If the family has men with the same version of jade, then the time of the onset of the terminal stage of renal failure can be easily predicted, it will be the same. Women do not have such a relationship.
In autosomal recessive type, renal failure develops slightly more slowly, but there is a risk that CRF will move to the terminal stage by the age of 30.
In autosomal dominant form, the course and predictions are most favorable: chronic kidney failure does not reach the situation. This form corresponds to benign family hematuria. Specific therapy in this case is not carried out, the presence of blood in the urine does not endanger human life. Only constant medical monitoring of the patient's condition is necessary.