Medullary cystic kidney disease Health Article

Definition

Medullary cystic kidney disease (MCKD) is a hereditary disorder in which cysts in the center of each kidney cause the kidneys to gradually lose their ability to work.

Alternative Names

Familial juvenile nephrophthisis; Senior-Loken syndrome

Causes, incidence, and risk factors

Medullary cystic kidney disease (MCKD) is very similar to the childhood disease familial juvenile nephronophthisis (NPH). Both lead to scarring of the kidney and formation of fluid-filled cavities (cysts) in the deeper parts of the kidney.

In these conditions, the kidneys don't concentrate the urine enough, leading to excessive urine production and loss of sodium.

MCKD occurs in older patients and is inherited in an autosomal dominant pattern. NPH occurs in young children and is usually due to autosomal recessive inheritance.

NPH may be associated with non-kidney features (like eye problems), while MCKD is limited to the kidneys.

Symptoms

Early in the disease, symptoms may include:

• Excessive urination (polyuria)
• Low blood pressure
• Need to urinate at night (nocturia)
• Salt cravings
• Weakness

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

• Coma
• Confusion
• Decreased alertness
• Delirium
• Drowsiness
• Easy bruising or bleeding
• Extreme sleepiness (lethargy)
• Fatigue
• Frequent hiccups
• General ill feeling
• Generalized itching
• Headache
• Increased skin pigmentation (skin may appear yellow or brown)
• Muscle twitching or muscle cramps
• Nausea
• Pale skin
• Reduced sensation in the hands, feet, or other areas
• Seizures
• Unintentional weight loss
• Vomiting blood or blood in the stool
• Weakness

Signs and tests

Laboratory tests that may be done include:

• 24-hour urine volume
• Blood pressure measurement (may be low)
• BUN (blood urea nitrogen)
• Complete blood count
• Creatinine level and creatinine clearance
• Urine specific gravity (will be low)

The following tests can help diagnose this condition:

• Abdominal ultrasound or abdominal CT scan
• Renal biopsy