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$Title{Valinemia}
$Subject{Valinemia Hypervalinemia Valine Transaminase Deficiency }
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Copyright (C) 1988, 1989 National Organization for Rare Disorders, Inc.

627:
Valinemia

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

Synonyms

     Hypervalinemia
     Valine Transaminase Deficiency

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.

Valinemia is a very rare metabolic disorder.  It is characterized by
elevated levels of the amino acid valine in the blood and urine caused by a
deficiency of the enzyme valine transaminase.  This enzyme is needed in the
breakdown (metabolism) of valine.  Infants with valinemia usually have a lack
of appetite, vomit frequently, and fail to thrive.  Low muscle tone
(hypotonia) and hyperactivity also occur.

Symptoms

Valinemia is usually present at birth.  Symptoms include lack of appetite,
frequent vomiting, and failure to thrive.  The levels of the amino acid
valine in the blood and urine are elevated.  Abnormally low muscle tone,
excessive drowsiness, and/or hyperactivity can also occur.  A diet low in
valine introduced during early infancy usually improves symptoms of
valinemia, and lowers the valine concentrations in the blood to normal
levels.

Causes

Valinemia is thought to be a genetic disorder inherited through 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 a person receives one normal gene and one gene
for the disease, he or she 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

Valinemia is a very rare disorder, occurring in less than 200 persons in the
United States.  It is present in affected infants at birth.

Therapies:  Standard

Valinemia is treated by following a diet low in the amino acid valine with
appropriate monitoring to avoid symptoms of valine deficiency.

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 Valinemia, 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 NDIC
     Bethesda, MD  20892
     (301) 468-2162

     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, please 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

A SIBSHIP WITH HYPERVALINEMIA:  O.S. Reddi, et al.; Human Genet (2 November
1977:  issue 39(1)).  Pp. 139-142.

THE METABOLIC BASIS OF INHERITED DISEASE, 5th ed.:  John B. Stanbury, et
al., eds; McGraw Hill, 1983.  Pp. 450-451.

MENDELIAN INHERITANCE IN MAN, 7th ed.:  Victor A. McKusick; Johns Hopkins
University Press, 1986.  P. 1294.