Causes

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 patients. 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.

Symptoms

Early in the disease, symptoms may include:

• Excessive urination (polyuria)
• Salt cravings
• Urination at night (nocturia)
• Weakness

Late in the disease, symptoms of kidney failure may develop, which include:

• Coma
• Confusion
• Decreased alertness
• Easy bruising or bleeding
• Fatigue
• Frequent hiccups
• Headache
• Increased skin color (skin may appear yellow or brown)
• Itching
• Malaise (general ill feeling)
• Muscle twitching or cramps
• Nausea
• Pale skin
• Reduced sensation in the hands, feet, or other areas
• Seizures
• Vomiting blood or blood in the stool
• Weight loss
• Weakness

Exams and Tests

Blood pressure may be low. The skin may be:

• Abnormally colored
• Dry
• Easy to bruise
• Pale

Tests that may be done include:

• 24-hour urine volume and electrolytes
• Blood urea nitrogen (BUN)
• Complete blood count (CBC)
• Creatinine - blood
• Creatinine clearance - blood and urine
• Uric acid - blood
• Urine specific gravity (will be low)

The following tests can help diagnose this condition:

• Abdominal CT scan
• Abdominal ultrasound
• Kidney biopsy
• Kidney ultrasound

Treatment

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 medications and diet changes, limiting foods containing phosphorus and potassium. You may need dialysis and a kidney transplant.

For detailed information on treatment, see:

• Chronic kidney failure
• End-stage kidney disease

Outlook (Prognosis)

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.

Possible Complications

• Anemia
• 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)
• Infertility
• Menstrual problems
• Miscarriage
• Pericarditis
• Peripheral neuropathy
• Platelet dysfunction with easy bruising
• Skin color changes

When to Contact a Medical Professional

Call for an appointment with your health care provider if you have any symptoms of medullary cystic disease.

Prevention

Medullary cystic kidney disease is an inherited disorder. It may not be preventable.

Alternative Names

Familial juvenile nephrophthisis; Senior-Loken syndrome

References

Arnaout MA. Cystic kidney disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 128.

Torres VE, Grantham JJ. Cystic diseases of the kidney. In: Brenner BM, ed. Brenner and Rector's the Kidney. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 41.

Updated: 4/19/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Herbert Y. Lin, MD, PHD, Nephrologist, Massachusetts General Hospital; Associate Professor of Medicine, Harvard Medical School. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.