Medullary cystic kidney disease
Medullary cystic kidney disease is an inherited condition in which cysts in the center of each kidney cause the kidneys to gradually lose their ability to work.
Familial juvenile nephronophthisis; Senior-Loken syndrome
Medullary cystic kidney disease (MCKD) is very similar to the childhood disease familial juvenile nephronophthisis (NPH). Both lead to scarring of the kidney and fluid-filled cavities (cysts) in the deeper parts of the kidney.
In these conditions, the kidneys do not concentrate the urine enough. This leads to too much urine production and the loss of sodium and other important chemicals from the blood.
MCKD occurs in older people. NPH is found in young children. Both conditions are inherited.
NPH may occur with eye or nervous system problems. MCKD is limited to the kidneys.
Early in the disease, symptoms may include:
- Excessive urination (polyuria)
- Salt cravings
- Urination at night (nocturia)
Late in the disease, symptoms of kidney failure may develop, which include:
- Decreased alertness
- Easy bruising or bleeding
- Frequent hiccups
- Increased skin color (skin may appear yellow or brown)
- Malaise (general ill feeling)
- Muscle twitching or cramps
- Pale skin
- Reduced sensation in the hands, feet, or other areas
- Vomiting blood or blood in the stool
- Weight loss
Exams and Tests
The health care provider will examine you and ask about your symptoms. The exam may reveal that your blood pressure is low. Your skin may be:
- Abnormally colored
- Easy to bruise
Tests that may be done include:
- 24-hour urine volume and electrolytes
- Blood urea nitrogen (BUN)
- Complete blood count (CBC)
- Creatinine blood test
- Creatinine clearance - blood and urine
- Uric acid blood test
- Urine specific gravity (will be low)
The following tests can help diagnose this condition:
There is no cure for this disease. At first, treatment focuses on controlling symptoms, reducing complications, and slowing the progression of the disease. Because so much water and salt are lost, you will need to drink plenty of fluids and take salt supplements to avoid dehydration.
As the disease gets worse, kidney failure develops. Treatment may involve taking medicines and diet changes, limiting foods containing phosphorus and potassium. You may need dialysis and a kidney transplant.
Most people with MCKD reach end-stage kidney disease between ages 30 and 50. Lifelong treatment may control the symptoms of chronic kidney disease. The cysts that occur with MCKD may be very small, but large numbers of them can lead to kidney problems.
MCKD may lead to the following health problems:
- Bone weakening and fractures
- Cardiac tamponade
- Changes in glucose metabolism
- Congestive heart failure
- End-stage kidney disease
- Gastrointestinal bleeding, ulcers
- Hemorrhage (excessive bleeding)
- High blood pressure
- Hyponatremia (low blood sodium level)
- Hyperkalemia (too much potassium in the blood), especially with end-stage kidney disease
- Hypokalemia (too little potassium in the blood)
- Menstrual problems
- Peripheral neuropathy
- Platelet dysfunction with easy bruising
- Skin color changes
When to Contact a Medical Professional
Call for an appointment with your provider if you have any symptoms of medullary cystic disease.
Medullary cystic kidney disease is an inherited disorder. It may not be preventable.
O'Toole JF, Hildebrandt F. Nephronophthisis and medullary cystic kidney disease. In: Gilbert SJ, Weiner DE, eds. National Kidney Foundation's Primer on Kidney Diseases. 6th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 42.
Torres VE, Grantham JJ. Cystic diseases of the kidney. In: Taal MW, Chertow GM, Marsden PA, Skorecki K, Yu A, Brenner BM, eds. Brenner and Rector's The Kidney. 9th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 45.