Alternative Names medullary cystic renal disease, nephronophthisis complex
Definition Medullary cystic disease (MCD) is an inherited condition that affects the kidneys. In this condition, multiple small fluid-filled sacs, called cysts, form inside the kidneys.
What is going on in the body? In medullary cystic disease, small cysts form in a part of the kidney called the medulla. Though MCD is inherited, the exact cause is not known. A problem of the tissue deep inside the kidneys is suspected. The end results of MCD include:
inflammation in the kidney, eventually leading to scarring
impairment in the ability of the kidneys to secrete and absorb salts
impaired ability of the kidneys to concentrate and dilute urine
There are different types of MCD. Each usually leads to kidney failure. The age at which kidney failure occurs depends partly on the type of MCD. Abnormalities in other areas of the body, such as vision changes, may also occur with some types of MCD. Most people with MCD either die from the disease or need permanent Dialysis or a kidney transplant. Dialysis is a procedure to filter the blood when the kidneys aren't working.
What are the signs and symptoms of the disease? Symptoms of medullary cystic disease often begin during childhood. However, in some forms of MCD, symptoms don't begin until adulthood. Common signs and symptoms of MCD include:
What are the causes and risks of the disease? Medullary cystic disease is inherited in different ways depending on the type of MCD. A child may need to inherit only one abnormal gene from one parent or one abnormal gene from each parent.
What can be done to prevent the disease? There are no known ways to prevent medullary cystic disease once a person has been born. Genetic counselling can be helpful to couples with a family history of this condition.
How is the disease diagnosed? Diagnosis of medullary cystic disease begins with a history and physical examination. Kidney function tests and urine cultures can detect infection or kidney damage. An ultrasound or CT scan can assess the kidney size or find kidney cysts.
In difficult cases, a kidney biopsy may be needed to make the diagnosis. This is a procedure that involves inserting a special needle through the skin and into the kidney. The needle is used to remove a tiny piece of the kidney, which can be sent to the laboratory for evaluation and testing.
What are the long-term effects of the disease? Kidney failure is the most likely long-term effect of medullary cystic disease. dialysis or kidney transplantation is needed to treat kidney failure or death will occur. Kidney failure can affect or damage almost any organ or part of the body. For instance, those with kidney failure may develop heart damage, infections, nerve damage, and weak bones.
What are the risks to others? Medullary cystic disease is not contagious. However, affected persons may pass MCD on to their children in some cases.
What are the treatments for the disease? Medullary cystic disease cannot be reversed, so treatment is directed at the complications. Treatment with fluids or salts may be needed to correct dehydration or salt imbalances. Blood transfusions may be needed to treat anaemia. The treatment options for kidney failure may include dialysis or kidney transplant. Surgery to remove a kidney may be needed if chronic abdominal pain occurs. Kidney infections are common and are treated with antibiotics. Other treatment will depend on any underlying conditions that result from MCD or kidney failure, such as visual impairments, high blood pressure, or infections.
What happens after treatment for the disease? Treatment usually lasts for life, as medullary cystic disease cannot be cured and usually gets worse over time. Once kidney failure occurs, dialysis is usually needed 3 times a week. If a kidney transplant is performed, the person will need lifelong treatment.
How is the disease monitored? The person's symptoms as well as kidney function tests are used to monitor the degree of kidney failure. Any new or worsening symptoms should be reported to the doctor.
Author: Rajnish K. Dhingra, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
