Signs & Symptoms of Thin Basement Membrane Disease

Thin basement membrane disease is a disorder affecting the human kidneys. It goes by several other names, including thin basement membrane nephropathy, thin glomerular basement membrane disease and benign familial hematuria. Thin basement membrane disease is relatively rare, affecting only 1 percent of the general population. It has a strong genetic component and tends to run in families.

Primary Symptoms

• Thin basement membrane disease is characterized by blood in the urine.

  The primary symptom of thin basement membrane disease is hematuria, or blood in the urine. Blood in the urine, however, might indicate many other disorders, including kidney stones, tumors or urinary tract infections. Because of this, individuals with this symptom should consult their doctors for further diagnosis. Another common symptom of thin basement membrane disease is proteinuria, or the presence of excess protein in the urine. While these urinary symptoms often cause distress or fear, the course of thin basement membrane disease is usually benign, or non-dangerous.

Secondary Symptoms or Complications

• Because thin basement membrane disease affects the kidneys, secondary symptoms and complications sometimes arise. In most cases, kidney function is intact and no further symptoms emerge. However, body swelling and significantly decreased urine production occur in some individuals. Up to 35 percent of people with thin basement membrane disease have high blood pressure, which often leads to complications involving heart and circulatory function. Kidney failure is a possible outcome in the severe progressive form of the illness, although it remains very rare.

Diagnosis

• Primary care physicians or specialists diagnose thin basement membrane disease. Urine tests are performed to detect red blood cells or elevated protein levels in the urine, which are indicators of the disease. Physicians usually perform a kidney biopsy to confirm the diagnosis. During this test, examination with an electron microscope reveals thinning of one of the layers of the kidney, the glomerular basement membrane.

Treatment

• Thin basement membrane disease is one of the most common diseases affecting the kidneys. In most cases, it has a benign course, meaning that no clinically significant problems arise and people with the disease live completely normal lives. In some cases, complications arise that require further treatment. Monitoring potassium levels, restricting fluid intake and managing high blood pressure help alleviate problems with kidney functioning. In extreme cases such as kidney failure, dialysis or kidney transplant may be necessary, although these complications remain rare.

Genetic Features

• Thin basement membrane disease has a strong genetic component, which causes a strong familial link. The illness is autosomal dominant, meaning that descendants of people with the disease are highly likely to also have the illness. There is some evidence linking thin basement membrane disease to mutations in the genes COL4A3 and COL4A4, although confirmatory genetic testing for the disease remains unavailable.