$Unique_ID{BRK03759}
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$Title{Fructosuria}
$Subject{Fructosuria Levulosuria Hepatic Fructokinase Deficiency Essential
Fructosuria Diabetes, Insulin-Dependent}
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Copyright (C) 1988, 1989 National Organization for Rare Disorders, Inc.

573:
Fructosuria

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

Synonyms

     Levulosuria
     Hepatic Fructokinase Deficiency
     Essential Fructosuria

Information on the following disorder can be found in the Related
Disorders section of this report:

Diabetes, Insulin-Dependent

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 physician and/or the agencies listed in the "Resources" section
of this report.

Fructosuria is a very rare inherited metabolic disorder.  It is
characterized by the excretion of fruit sugar (fructose) in the urine.
Normally, no fructose is excreted in the urine.  This condition is caused by
a deficiency of the enzyme fructokinase in the liver.  This enzyme is needed
for the synthesis of glycogen (the body's form of stored energy) from
fructose.  The presence of fructose in the blood and urine may lead to an
incorrect diagnosis of Diabetes Mellitus.

Symptoms

Fructosuria is characterized by the presence of fructose in the urine.  There
are no other symptoms.  However, the fructose may be mistaken for glucose
(blood sugar) leading to an incorrect diagnosis of Diabetes Mellitus.

Causes

Fructosuria is a rare hereditary disorder transmitted by autosomal recessive
genes.  (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 for the same
trait 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 25 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.)

Affected Population

Fructosuria affects about 1 out of every 130,000 persons in the United
States.  It affects males and females in equal numbers.

Related Disorders

Comparison of the following disorder with Fructosuria may be useful for a
differential diagnosis:

Diabetes Mellitus is a common disorder in which the body does not produce
enough insulin and is, therefore, unable to convert nutrients into the energy
necessary for daily activity.  The disorder affects females and males
approximately equally.  Although the causes of Insulin-Dependent Diabetes are
not known, genetic factors seem to play a role.  Symptoms of Diabetes
Mellitus can be very debilitating if left untreated, whereas Fructosuria does
not cause excessive thirst, weight loss or fatigue.  (For more information,
choose "Diabetes" as your search term in the Rare Disease Database.)

Therapies:  Standard

Diagnosis of Fructosuria is made by testing the urine for the presence of
fructose.  Fructosuria does not require treatment as the symptoms are
harmless.

Therapies:  Investigational

This disease entry is based upon medical information available through
December 1988.  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 Fructosuria, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     (203) 746-6518

     National Digestive Diseases Information Clearinghouse
     Box NDDIC
     Bethesda, MD  20892
     (301) 468-6344

     Research Trust for Metabolic Diseases in Children
     Golden Gates Lodge, Weston Rd.
     Crewe CW1 1XN, England
     Telephone:  (0270) 250244

For information on genetics and genetic counseling referrals, contact:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY  10605
     (914) 428-7100

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     (301) 652-5553

References

MENDELIAN INHERITANCE IN MAN, 7th ed.:  Victor A. McKusick; Johns Hopkins
University Press, 1986.  P. 978.

ESSENTIAL FRUCTOSURIA, HEREDITARY FRUCTOSE INTOLERANCE, AND FRUCTOSE-1,6-
DIPHOSPHATASE DEFICIENCY:  R. Gitzelmann, et al.; In:  THE METABOLIC BASIS OF
INHERITED DISEASE, 5th ed.:  John B. Stanbury, et al.; McGraw Hill, 1983.
Pp. 118-140.