Polycystic Kidney Disease
What is it?
Polycystic kidney disease, or
PCKD, is an inherited kidney disorder in which
multiple cysts grow in the kidneys, destroying
normal kidney tissue. These
cysts, fluid-filled sacs, cause the kidneys to become enlarged, and
interfere with the function of the kidneys.
Who gets it?
PKD affects people of all races
throughout the world. Because it is an inherited
defect, children of a parent with PKD have a 50
percent chance of inheriting the disease. It is unknown what exact mechanism
triggers the cysts to form. It occurs in both
children and adults, but is much more common in
adults. Often, symptoms are not seen until middle
age.
What causes it?
PKD is caused by a genetic
defect. In very simple terms, genes are carried on
thread-like structures called chromosomes, and
determine our individual characteristics. Just one
missing or faulty gene or chromosome can cause a
birth defect. PKD has two forms. When a child
inherits one PKD gene from one parent, called
dominant inheritance, symptoms usually begin
sometime during adulthood. However, when children
inherit two PKD genes, one from each parent, it is
called recessive inheritance. This type of PKD is
severe and often fatal in infancy. In some cases,
PKD is not inherited, but occurs as a spontaneous
gene mutation.
What are the symptoms?
The most common symptoms of
PCKD are frequent infections, blood in the urine,
anemia, kidney stones, heart murmur, brain
aneurysm, and hernia. The abdominal pain may be felt in any part of the
abdomen, or it may be limited to the right upper
or left upper quadrant of the abdomen. Other less
common symptoms include nail abnormalities,
painful menstruation, joint pain, drowsiness, and
high blood pressure.
Infants born with PKD are often stillborn, or
die within the first few years of life. Infants
with PKD have distinctive facial features. The
ears appear floppy and the eyes lay within folds
of skin. The baby’s nose is pointed and the chin
is small. Infants with PKD often have trouble
breathing because the lungs are poorly developed.
Adult symptoms usually begin after age 30 as
the cysts gradually enlarge, destroying healthy
kidney tissue and increasing kidney size. The
pressure from the enlarged kidneys causes back
pain and abdominal swelling. The kidneys begin to
have difficulty filtering waste products from the
blood, which causes nausea, fatigue, and low urine
production. Untreated, PKD causes complete kidney
failure. Many patients with PKD also have cysts on
the liver and the pancreas.
How is it Diagnosed?
To diagnose PKD, your doctor will take a
complete medical history and perform a thorough
physical examination. He or she will be able to
feel any enlargement of the kidneys if the disease
has progressed. Your doctor will order tests that
evaluate your kidney function, as well as scans of
the kidney area to check for enlargement and
cysts. He or she may perform a kidney biopsy, in
which a small sample of kidney tissue is removed
for examination under a microscope. Your doctor
will also check for high blood pressure and any
heart conditions that often accompany PKD.
Laboratory test can include a urinalysis which
may show protein or blood in the urine. A complete
blood count may show a decreased or an increased
number of red blood cells, or hematocrit. The cysts may be seen
on radiologic exams such as an abdominal
ultrasound, and abdominal CT scan, and abdominal
MRI scan, or an intravenous pyelogram (IVP).
What is the Treatment?
Currently there is no treatment that will
prevent the cysts from forming once the disease
has been triggered. Your doctor will focus on
controlling your symptoms, preventing infection,
and maintaining kidney function. Your doctor will
monitor your symptoms through regular examinations
and diagnostic tests. It is extremely important to
keep blood pressure at normal levels. High blood
pressure puts a strain on the kidneys because they
have to work even harder to get rid of the extra
salt and water in the blood. High blood pressure
is generally treated with medications and a low
salt diet. Patients with anemia are given iron
supplements, and infections are treated with
antibiotics.
Surgical treatment
Surgery is necessary only when cysts bleed or
become infected. Patients with failing kidneys
need kidney dialysis, a process in which the waste
products are filtered from the blood for the
kidneys. A kidney transplant is the only
alternative when dialysis is no longer effective. Surgical drainage of the cysts
may be necessary because of pain, bleeding,
infection or obstruction. Surgery to remove one or
both kidneys may also become necessary. Kidney
transplantation is also a way to treat patients
with PCKD that have progressed to end stage renal
disease.
Self-care tips
Because PKD is an inherited disease, there is
currently no known way to prevent it. If you have
been diagnosed with PKD, follow your doctors
recommendations for treatment. Follow a balanced,
healthy diet that is low in salt, and avoid
alcohol and cigarette smoking.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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