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$Unique_ID{BRK04118}
$Pretitle{}
$Title{Polycystic Kidney Diseases}
$Subject{Polycystic Kidney Diseases Polycystic Renal Diseases Infantile
Polycystic Kidney Disease Juvenile Polycystic Kidney Disease Adult Polycystic
Kidney Disease}
$Volume{}
$Log{}

Copyright (C) 1986, 1987, 1990, 1991, 1992 National Organization for Rare
Disorders, Inc.

237:
Polycystic Kidney Diseases

** IMPORTANT **
It is possible the main title of the article (Polycystic Kidney Diseases)
is not the name you expected.  Please check the SYNONYMS listing to find the
alternate names and disorder subdivisions covered by this article.

Synonyms

     Polycystic Renal Diseases

DISORDER SUBDIVISIONS

     Infantile Polycystic Kidney Disease
     Juvenile Polycystic Kidney Disease
     Adult Polycystic Kidney Disease

General Discussion

** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.


Polycystic Kidney Diseases are inherited disorders that are characterized
by many cysts in both kidneys (bilateral).  This causes enlargement of the
total kidney size, while reducing the functional kidney tissue by
compression.

Symptoms

There are two forms of this disorder, one affecting children and another
affecting adults.

The onset of the Infantile form of Polycystic Kidney Disease is soon
after birth.  It is an autosomal recessively inherited disease.  The abdomen
is enlarged and the kidneys are palpable.  Infants with this disorder often
suffer from dehydration and emaciation.  In the juvenile form of Polycystic
Kidney disease, fibrosis of the liver often occurs.  It is frequently
associated with high blood pressure (hypertension) and an enlarged spleen.

The adult form of Polycystic Kidney disease is an autosomal dominant
inherited disorder which progresses to renal insufficiency in middle age.  In
this type of the disorder, clinical symptoms usually develop after the second
decade of life.  Symptoms are usually related to pressure effects of the
cysts and include discomfort or pain in the loin (lumbar) area, blood in the
urine (hematuria), infection, and colic.  A loss of kidney function may occur
resulting in accumulation of by-products of protein metabolism in the blood
(uremia).  In addition, chronic infection of the kidney can occur
contributing to a progressive loss of kidney function.  In about one third of
cases, cysts are present in the liver, but they are of no functional
significance.  There is also a high associated incidence of localized
widening of arteries inside the skull (intracranial aneurysms).  Hypertension
is found in about half of the patients at the time of diagnosis.  The spleen
is often enlarged.

Although approximately one half of patients with Polycystic Kidney
Disease develop kidney failure (uremia) within ten years after onset of
symptoms, the course of the disorder is quite variable and many patients will
go for more than 20 years before renal failure occurs.  Complications of
hypertensive cardiovascular disease occur at an average age of 50 years.

Causes

The infantile form of Polycystic Kidney disease as an autosomal recessively
inherited disorder.  The adult form is inherited as an autosomal dominant
trait.  This dominant form of Polycystic Kidney Disease has been found to be
caused by more than one defective gene.  The defective genes are so closely
linked on the short arm of chromosome 16 that they are usually inherited
together.  Only about five percent of people with the disorder do not inherit
the genes together.  These variations can account for clinical differences in
patients with the disorder.  In cases where Polycystic Kidney Disease is
caused by a mutation, onset of the disorder occurs much later in life.
Scientists hope that these discoveries will help them identify carriers
before the disease has had a chance to develop.

Human traits including the classic genetic diseases, are the product of
the interaction of two genes for that condition, one received from the father
and one from the mother.

In recessive disorders, the condition does not appear unless a person
inherits the same defective gene from each parent.  If one receives one
normal gene and one gene for the disease, the person will be a carrier for
the disease, but usually will show no symptoms.  The risk of transmitting the
disease to the children of a couple, both of whom are carriers for a
recessive disorder, is twenty-five percent.  Fifty percent of their children
will be carriers, but healthy as described above.  Twenty-five percent of
their children will receive both normal genes, one from each parent and will
be genetically normal.

In dominant disorders, a single copy of the disease gene (received from
either the mother or father) will be expressed "dominating" the normal gene
and resulting in appearance of the disease.  The risk of transmitting the
disorder from affected parent to offspring is 50% for each pregnancy
regardless of the sex of the resulting child.)  Unlike standard dominant
disorders, Polycystic Kidney Disease can involve more than one dominant gene
on the same chromosome.

In 1985, medical investigators reported that chromosome 16 carries the
defective genes responsible for the autosomal dominant form of Polycystic
Kidney Disease.

Affected Population

Polycystic Kidney Disease affects approximately 500,000 Americans.  This
disorder comprises eight to ten percent of cases of end stage renal (kidney)
disease (ESRD), which is a leading cause of kidney failure in the United
States.

Related Disorders

Medullary Cystic Disease is a diffuse kidney disorder which appears in
children and young adults.  It is characterized by the gradual appearance of
urea and other by-products of protein breakdown in the blood.  (For more
information on Medullary Cystic Disease, choose Medullary Cystic Disease as
your search term in the Rare Disease Database.)

Medullary Sponge Kidney is characterized by dilatation of the terminal
collecting ducts in the kidney.  Often small calcium oxalate stones appear
in the ducts.  (For more information on this disorder, choose "sponge" as
your search term in the Rare Disease Database).

Glomerular Cystic disease is very similar to PKD, but the liver and
spleen are normal in patients with glomerular cystic disease.

Therapies:  Standard

Treatment of Polycystic Kidney disease consists of management of urinary
infections and secondary hypertension.  Genetic counseling to families with
the disorder is recommended.  When uremia occurs it is managed by an
increase in intake of calories combined with a reduction in total content of
dietary protein.  It is important that sufficient carbohydrates and fat are
provided to meet energy requirements.

With dialysis, patients with Polycystic Kidney disease regain a normal
red cell volume in the blood (hematocrit).  Transplantation of a kidney is
sometimes indicated, but the use of parental and sibling donors may be
impractical in view of the familial characteristics of the disease.

Magnetic Resonance Angiography (MRA) may be used for screening of
intracranial aneurysms in patients with autosomal dominant Polycystic Kidney
Disease.  This screening is typically used on patients with a family history
of intracranial aneurysm, those who have symptoms that suggest an
intracranial aneurysm, patients who have elective surgery and/or those who
are in high-risk occupations.

Therapies:  Investigational

Calcium Acetate is a new orphan drug being used in the treatment of
hyperphosphatemia in end stage renal disease (ESRD).  It is manufactured by
Pharmedic Co., 130 Exmoor Ct., Deerfield, IL  60015.

Research on Autosomal Recessive Polycystic Kidney Disease (ARPKD) that
affects children is being pursued by the following research team:

     Lisa M. Guay-Woodford, M.D.
     Norman D. Rosenblum, M.D.
     Kathy L. Jabs, M.D.
     William E. Harmon, M.D.
     E. William Harris, Jr., M.D., Ph.D.
     The Division of Nephrology
     The Children's Hospital
     300 Longwood Ave.
     Boston, MA  02115
     [phone]

Clinical trials are underway to study intracranial aneurysms in autosomal
dominant Polycystic Kidney Disease.  Interested persons may wish to contact:

     William D. Kaehny, M.D.
     Box C83, University of Colorado Health Science Center
     4200 E. Ninth Ave.
     Denver, CO  80262
     [phone]

to see if further patients are needed for this research.

This disease entry is based upon medical information available through
November 1992.  Since NORD's resources are limited, it is not possible to
keep every entry in the Rare Disease Database completely current and
accurate.  Please check with the agencies listed in the Resources section for
the most current information about this disorder.

Resources

For more information on Polycystic Kidney Disease, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     Polycystic Kidney Disease Research Foundation
     20 West Ninth Street
     Kansas City, MO 64105
     [phone]

     National Kidney and Urologic Diseases Information Clearinghouse
     Box NKUDIC
     Bethesda, MD  20892
     [phone]

     The National Kidney Foundation
     2 Park Ave.
     New York, NY  10016
     [phone]
     [phone]

     American Kidney Fund
     6110 Executive Blvd., Suite 1010
     Rockville, MD  20852
     [phone]
     [phone]
     [phone] (MD)

     National Association of Patients on Hemodialysis and Transplantation
     150 Nassau Street
     New York, NY 10038
     [phone]

For information on genetics and genetic counseling referrals, please
contact:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY  10605
     [phone]

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     [phone]

References

CECIL TEXTBOOK OF MEDICINE, 18th ed.:  James B. Wyngaarden, and Lloyd H.
Smith, Jr., Eds.:  W.B. Saunders Co., 1988.  Pp. 148, 506, 644-7.

THE MERCK MANUAL 15th ed:  R. Berkow, et al:  eds; Merck, Sharp & Dohme
Research Laboratories, 1987.  P. 1630.

THE DIAGNOSIS AND PROGNOSIS OF AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY
DISEASE, Patrick S. Parfrey, M.D., et al.; n Eng J Med (October 18, 1990,
issue 323, (16)).  Pp. 1085-1090.