Alport syndrome

Alport 's syndrome, also called progressive hereditary nephritis, an inherited disease with malformed collagen fibers of type IV is It was first described by Arthur Cecil Alport in South Africa.

Frequency

Alport syndrome is the most common hereditary chronic progressive nephropathy with renal failure. The prevalence is approximately 1:7500. 80 % of those affected are male.

Cause

So far, 50 different mutations known to cause defects in the α - chain of type IV collagen which occurs in the basement membrane of the inner ear and kidney. Depending on the location of the mutation various modes of inheritance may be present:

• In 80 % of cases there is an X-linked dominant inheritance. The mutation is located on Xq -22, affected the gene col4 A5.
• At 10 % there is an autosomal recessive mode of inheritance, the mutation is located on chromosome 2, locus q35 - 36th The affected genes may be col4 col4 A3 or A4.
• Approx. 10% of cases based on new mutations.
• Very rarely the Alport syndrome is based on an autosomal dominant inheritance.

Symptoms

The first symptom is usually a hematuria (blood in urine), arrives at the then proteinuria (protein in the urine ) is added. In young adulthood occurs in 50 % of cases of bilateral sensorineural hearing loss, especially in the frequency range 2000-8000 Hz in about 10% it comes to eye changes, usually by a cone- shaped protrusion of the eye lens ( lenticonus ) or cataract and fundus changes. In the course of the chronic progressive renal failure that makes mostly at the beginning of the second decade of life renal replacement therapy necessary developed.

Diagnosis

With a positive family history, hearing loss, and hematuria is suspected presence of Alport syndrome. Can be hedged diagnosis by renal biopsy or molecular genetic analysis.

Therapy

The course of the disease was until recently considered to be fateful, although a molecular genetic diagnosis in infancy is possible before the outbreak of the disease.

Promising study results suggest that a preventive therapy with ACE inhibitors can delay the progression of kidney disease by several years. It is believed that - in addition to the damage to the kidneys by the Alport syndrome itself - especially the resulting by the renal high blood pressure damages the kidneys function. Therefore, an early onset blood pressure treatment with low target values ​​(120 /80) is particularly important.

Despite these promising therapeutic approaches is no causal therapy available. If the renal failure is so severe that a threatening uremia would occur without treatment, starting with dialysis. It should also, where necessary, the arterial blood pressure with ACE-inhibitors below 130/ 80 mmHg is maintained, since it slows down the progress of the disease. As a further option, the kidney may be considered.

Forecast

Because of the X - chromosomal inheritance affects mainly men. The course is highly variable, it often happens, however, already in young adulthood to a terminal and thus renal insufficiency requiring dialysis.