CD-ROM Today 1996 January/CD-ROM Today 1996 January.iso/dp/0383/03838.txt

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$Unique_ID{BRK03838}
$Pretitle{}
$Title{Hyperchylomicronemia}
$Subject{Hyperchylomicronemia Buerger-Gruetz Syndrome Exogenous
Hypertriglyceridemia Fredrickson Type I Hyperlipoproteinemia Essential
Familial Hyperlipemia Fat-Induced Hyperlipemia Idiopathic Familial
Hyperlipemia Retention Hyperlipemia Hyperlipidemia I Hyperlipoproteinemia Type
I Lipoprotein Lipase Deficiency, Familial Familial Apolipoprotein C-II
Deficiency Hyperlipoproteinemia Type V}
$Volume{}
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Copyright (C) 1987, 1988, 1989 National Organization for Rare Disorders,
Inc.

474:
Hyperchylomicronemia

** IMPORTANT **
It is possible the main title of the article (Hyperchylomicronemia) is
not the name you expected.  Please check the SYNONYMS listing on the next
page to find alternate names, disorder subdivisions, and related disorders
covered by this article.

Synonyms

     Buerger-Gruetz Syndrome
     Exogenous Hypertriglyceridemia
     Fredrickson Type I Hyperlipoproteinemia
     Essential Familial Hyperlipemia
     Fat-Induced Hyperlipemia
     Idiopathic Familial Hyperlipemia
     Retention Hyperlipemia
     Hyperlipidemia I
     Hyperlipoproteinemia Type I
     Lipoprotein Lipase Deficiency, Familial

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

     Hyperlipoproteinemia Type V
     Familial Apolipoprotein C-II Deficiency

General Discussion

** IMPORTANT **
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.


Hyperchylomicronemia is a rare hereditary inborn error of metabolism
characterized by a massive accumulation of fatty droplets (chylomicrons) in
blood plasma, and a corresponding increase of the blood plasma concentration
of fatty substances called triglycerides.  The concentration of another fatty
substance called "very low density lipoprotein" (VLDL) is usually normal.
The disorder is caused by the absence of the enzyme lipoprotein lipase.

Symptoms

Hyperchylomicronemia is characterized by an abnormally high blood
concentration of droplets of a fatty substance called chylomicrons after a
patient eats fatty foods.  The first symptoms are skin lesions called
eruptive xanthomas.  These xanthomas are raised whitish-yellow colored skin
nodules on a slightly red base.  They vary in size from 0.1 to 0.3 inches in
diameter, but are often clustered and may grow together to form larger
plaques.  The number of nodules may vary from a few to hundreds.  They are
usually located over the buttocks, shoulders, and extremities.  However,
lesions may be found on any site including the face and mucous membranes.
Patients may mistake the lesions for acne.  Eruptive xanthomas are neither
painful nor itchy.  They usually appear within a few days after triglyceride
levels in the blood plasma have begun to increase.  They contain a yellowish
greasy substance and sometimes milky fluid.  They disappear again when the
increased fat in blood plasma (lipemia) starts to vanish.  Only a slight
discoloration finally remains.

Besides the skin symptoms, the most common manifestations of
Hyperchylomicronemia are episodes of abdominal pain.  Intensity, duration,
and localization of episodes are variable.  The attacks may be associated
with lack of appetite (anorexia), nausea, abdominal distension, fever, and
diarrhea.  Some patients with the disorder may not experience abdominal pain.
Inflammation of the pancreas, sometimes with bleeding, often occurs when
triglyceride levels are excessively high.  Enlargement of the liver and
spleen occurs particularly among infants and children with
Hyperchylomicronemia.  The enlargement of these organs may vary, often in
parallel with the fat content of the diet.  Large cells that swallow other
cell material (macrophages) that have incorporated chylomicrons often appear
in the spleen and sometimes in bone marrow of these patients.

In the presence of excessive fatty substances in the blood (hyperlipemia)
the arteries and veins in the outer parts of the eye's retina have a milky or
tomato juice appearance.  The back of the eyeball (fundus) may appear pale
pink upon examination by an ophthalmologist.  The change is related to the
degree of lipemia.  The retina may contain white fatty deposits.  Blood
circulation in the retina may also become disturbed, and narrowing of the
blood vessels and bleeding may occasionally occur.  These symptoms can affect
the vision of patients with Hyperchylomicronemia.

Causes

Hyperchylomicronemia is a 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
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.)

The disorder is caused by a deficiency of the enzyme lipoprotein lipase
which normally breaks down the fatty substances called lipoproteins.  This
results in an excessively high level of chylomicrons in the blood.

Affected Population

Hyperchylomicronemia is a very rare disorder which is present at birth.  It
affects males and females in equal numbers.

Related Disorders

Symptoms of the following disorders are similar to those of
Hyperchylomicronemia.  Comparisons may be useful for a differential
diagnosis:

Hyperlipoproteinemia Type V (Mixed Hyperlipemia) is thought to be a
recessive hereditary disorder characterized by an abnormally high level of
chylomicrons in the blood.  Other fatty substances called prebetalipoproteins
are also present in high concentrations in the blood.  Blood plasma has a
milky white appearance.  During overnight refrigeration of plasma, a layer of
chylomicrons rises to the top.  The underlying plasma is cloudy in patients
with Hyperchylomicronemia Type V, but clear in those with Type I of the
disorder.  Fatty changes in the retina of the eye may occur in both of these
disorders.  However, Type V is less severe than Type I Hyperlipoproteinemia.

Familial Apolipoprotein C-II Deficiency is a rare autosomal recessive
hereditary disorder.  It is characterized by a deficiency of apolipoprotein
C-II, a factor needed for functioning of the enzyme lipoprotein lipase,
causing an accumulation of chylomicrons and very low density lipoproteins
(VLDL) in blood plasma.  Recurrent attacks of pancreas infection
(pancreatitis) may also occur.

Therapies:  Standard

Restriction of fat in the diet is the most effective treatment for
Hyperchylomicronemia.  However, at the same time an adequate intake of
essential fatty acids must be maintained.  The reduction of fat in the diet
must be compensated by an increase in carbohydrates.  Part of the fat
calories can be supplied in the form of medium-chain triglycerides (MCT),
though many patients do not tolerate these well.  Additionally, the use of
alcohol and drugs such as estrogens (which increase synthesis of
triglycerides in the body), should be avoided.  During pregnancy patients
with Hyperchylomicronemia need strict dietary control and monitoring of blood
triglyceride levels.  Genetic counseling is recommended for families of
children with Hyperchylomicronemia.

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 Hyperchylomicronemia, please contact:

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

     National Digestive Diseases Information Clearinghouse
     Box NDDIC
     Bethesda, MD  20892
     [phone]

     Research Trust for Metabolic Diseases in Children
     Golden Gates Lodge, Weston Rd.
     Crewe CW1 1XN, England
     Telephone:  [phone]

For genetic information 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

THE METABOLIC BASIS OF INHERITED DISEASE, 5th ed.:  John B. Stanbury, et al.,
ed.; McGraw Hill, 1983.  Pp. 622-632.

MENDELIAN INHERITANCE IN MAN, 6th ed.:  Victor A. McKusick; Johns Hopkins
University Press, 1986.  P. 1042.

LIPAEMIA RETINALIS IN A 29-DAY-OLD INFANT WITH TYPE I
HYPERLIPOPROTEINAEMIA:  S. Hayasaka, et al.; British Journal Ophthalmol
(April 1985:  issue 69(4)).  Pp. 280-282.