What is polycystic kidney disease (PKD)?
Polycystic kidney disease (PKD) is a genetic disorder characterized by
the growth of numerous cysts filled with fluid in the kidneys. PKD cysts
can reduce kidney function, leading to kidney failure. PKD can also cause
cysts in the liver and problems in other organs, such as the heart and
blood vessels in the brain.
PKD is the fourth leading cause of kidney failure and affects approximately
500,000 people in the US. According to the National Institute of Diabetes
and Digestive and Kidney Diseases (NIDDK), about one-half of people with
autosomal dominant PKD progress to kidney failure, or end-stage renal
disease (ESRD).
What are the different types of PKD?
There are two primary inherited forms of PKD and one non-inherited form:
| autosomal
dominant PKD (inherited) |
This is the most common
inherited form of polycystic kidney disease, accounting for about
90 percent of all PKD cases. "Autosomal dominant" means that if one
parent has the disease, there is a 50 percent chance that the disease
will pass to a child, and that both males and females are equally
affected.
Usually, at least one parent must have the disease for a child to
inherit it. In 25 percent of cases, there is no family history of
PKD. These cases are new mutations in a family. Parents would not
be at increased risk to have additional children with PKD, but the
child with PKD would have a 50/50 chance to pass the gene on to his/her
children.
Autosomal dominant PKD is often called the adult polycystic kidney
disease. Symptoms usually develop between the ages of 30 and 40
(but they can begin as early as childhood), and may include the
following:
- abdominal pain
- detectable abdominal mass
- pale color to skin
- bruise easily
- high blood pressure
- kidney stones
- aneurysms (bulging of the walls of blood vessels) in the brain
- diverticulosis (pouches in the intestines)
- urinary tract infections
- hematuria (blood in the urine)
- liver and pancreatic cysts
- abnormal heart valves
Autosomal dominant PKD may occur with other conditions including:
- tuberous sclerosis - a genetic syndrome involving seizures,
mental retardation, benign tumors, and skin lesions.
- liver disease
- severe eye problems (cataracts or blindness)
The symptoms of autosomal dominant PKD may resemble other conditions
or medical problems. Always consult your child's physician for a
diagnosis.
Diagnosis of autosomal dominant PKD may include the use of imaging
techniques to detect cysts on the kidney and other organs, and a
review of the family history of autosomal dominant PKD. There are
three different dominant genes which have been identified that further
subdivide autosomal dominant PKD into PKD1, PKD2, and PKD3.
A physician will establish a treatment protocol for autosomal dominant
PKD only after careful consideration of the child's symptoms and
medical history. Treatment may include:
- pain medication
- surgery to shrink cysts and relieve pain
- treatment for high blood pressure
- treatment for urinary tract infections
- dialysis
- kidney transplantation
|
| autosomal
recessive PKD (inherited) |
Autosomal recessive PKD is a rare, inherited form of polycystic
kidney disease thought to be caused by a particular genetic flaw
that is different from the genetic flaw that causes autosomal dominant
PKD. Parents who do not have the disease can have a child with the
disease, if both parents carry the abnormal gene and both pass the
gene to their child. Carrier parents have a 25 percent chance, with
each pregnancy, to have a child with this type of PKD. Males and
females are equally affected. Autosomal recessive PKD is sometimes
detected prenatally (before birth) using a fetal ultrasound.
Symptoms of autosomal recessive PKD can begin before birth. In most
cases, the earlier the onset, the more severe the outcome. There
are four different types of autosomal recessive PKD, depending upon
the child's age when symptoms become evident:
- perinatal form - present at birth
- neonatal form - presents within the first month of life
- infantile form - presents between 3 and 6 months of age
- juvenile form - presents after 1 year of age
Children born with autosomal recessive PKD may develop kidney failure
within a few years and often experience the following:
- high blood pressure
- urinary tract infections
- frequent urination
The disease also usually affects the liver, spleen, and pancreas,
resulting in low blood cell counts, varicose veins, and hemorrhoids.
The symptoms of autosomal recessive PKD may resemble other conditions
or medical problems. Always consult your child's physician for a
diagnosis.
Diagnosis often includes ultrasound imaging of the fetus or newborn
to reveal cysts in the kidneys. Ultrasound examination of kidneys
of relatives may also be helpful.
Your child's physician will establish a treatment protocol for
autosomal recessive PKD only after careful consideration of the
child's symptoms and medical profile. Treatment may include:
- treatment for high blood pressure
- treatment for urinary tract infections
- hormonal therapy
- dialysis
- kidney transplantation
|
| acquired
cystic kidney disease, or ACKD (non-inherited) |
Acquired cystic kidney disease (ACKD) may develop in association
with long-term kidney problems, especially in persons who have kidney
failure and who have been on dialysis for a long time. Therefore,
it tends to occur later in life, and is an acquired, not inherited,
form of PKD.
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