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$Unique_ID{BRK03408}
$Pretitle{}
$Title{Acanthocytosis}
$Subject{Acanthocytosis Abetalipoproteinemia Bassen-Kornzweig Syndrome
Low-Density Beta Lipoprotein Deficiency Tangier Disease
(Alphalipoproteinemia)}
$Volume{}
$Log{}

Copyright (C) 1987, 1988, 1989 National Organization for Rare Disorders, Inc.

445:
Acanthocytosis

** IMPORTANT **
It is possible the main title of the article (Acanthocytosis) 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

     Abetalipoproteinemia
     Bassen-Kornzweig Syndrome
     Low-Density Beta Lipoprotein Deficiency

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

     Tangier Disease (Alphalipoproteinemia)

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.


Acanthocytosis is a digestive disorder which is characterized by the
absence of very low density lipoproteins (VLDL) and chylamicrons in the
plasma, and fat malabsorption resulting in excessive fats excretion
(steatorrhea).  Other symptoms include abnormal red blood cells
(acanthocytes), a vision disorder (retinitis pigmentosa), and impaired muscle
coordination (ataxia).

Symptoms

Symptoms of Acanthocytosis usually begin during the first year of life.  They
may include:

DIGESTIVE
Digestive tract symptoms may include poor appetite, vomiting, loose
voluminous stools, and diminished absorption of nutrients from food.  The fat
content of the intestinal mucous membrane cells tends to be very high.
Although patients with this disorder do not metabolize these fats well, only
15 to 20% of the ingested fat is excreted in the stool.  Fat-soluble vitamins
such as vitamins A, E, and K are also poorly absorbed.  The resulting vitamin
K deficiency causes blood clotting factor levels to diminish.

NEUROMUSCULAR
Infants with Acanthocytosis usually grow slowly.  They may lose stretch
reflexes.  At least one third of affected children have neuromuscular
problems during the first decade of life.  Poor muscle coordination (ataxia)
usually develops before age 20.  Only a few patients with Acanthocytosis are
able to stand unassisted by their fourth decade of life because
spinocerebellar degeneration causes loss of position and vibratory sensation.
(For more information, choose "ataxia" as your search term in the Rare
Disease Database.)  Loss of the fatty layer around some nerve cells
(demyelination) in the posterior spinal column may also occur.  Some loss of
pain, temperature and touch sensations may also develop.  Mental retardation
occurs in about one third of patients.  Weakness and muscle wasting (atrophy)
may occur, and in rare cases, heart problems may develop.

SKELETAL
Backward curvature (lordosis) or backward and sideways curvature of the
spine (kyphoscoliosis), a highly arched foot (pes cavus) or clubfoot may
occur in people affected with this disorder.  These skeletal abnormalities
probably result from muscle imbalances during crucial stages of bone
development.

OCULAR
Night blindness with rapidly progressing retinal disease (Retinitis
Pigmentosa, also known as RP) are other symptoms of Acanthocytosis.
Retinitis Pigmentosa usually starts at about 10 years of age.  Loss of clear
vision may begin sometime between the ages of 7 and 30 years, and can
progress to blindness.  Involuntary rapid movement of the eye (nystagmus) is
common in this disorder.  Paralysis of the eye muscles (ophthalmoplegia) may
also occur.  (For more information on this disorder, choose "RP" as your
search term in the Rare Disease Database.)

BLOOD - LYMPH
Abnormal red blood cells (acanthocytes) are present in this disorder.
Plasma cholesterol in the blood falls to a very low level.  Low-density
betalipoproteins are absent or severely deficient in blood plasma.  There is
lack of formation of fat-containing droplets in the lymph vessels
(chilomicrons) after eating fats.

Causes

Acanthocytosis is a hereditary disorder caused by autosomal recessive genes.
In many cases this disorder is found when parents of patients with
Acanthocytosis are blood relatives.  Doubling of the mutant gene probably
occurs in these cases.  (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.)

Affected Population

Acanthocytosis is a very rare disorder.  Symptoms usually first appear during
the first year of life.  Males and females are affected in equal numbers.

Related Disorders

Symptoms of the following disorder can be similar to those of Acanthocytosis.
Comparisons may be useful for a differential diagnosis:

Tangier Disease (Alphalipoproteinemia) is an inherited blood disorder
characterized by decreased concentrations of fat compounds in the blood
called high density lipoproteins.  Large amounts of these compounds may
accumulate in certain organs of the body causing tissue discoloration.  In
later stages, these accumulations may cause liver and spleen enlargement
and/or neurological problems.  (For more information on this disorder, choose
"Tangier" as your search term in the Rare Disease Database.)

Therapies:  Standard

Dietary restriction of long chain fatty acid triglycerides may relieve
gastrointestinal symptoms.  Large doses of Vitamin E prescribed under a
doctor's supervision may improve the muscle symptoms of Acanthocytosis and
can prevent retinal disease (retinopathy) in some patients affected with this
disorder.  However, Vitamin E does not stop progression of the disease.
Other treatment is symptomatic and supportive.  Social service agencies may
be helpful for mentally retarded and/or blind children and their families.
Genetic counseling is recommended for families of children with
Acanthocytosis.

Therapies:  Investigational

This disease entry is based upon medical information available through June
1990.  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 Acanthocytosis, 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]

     National Tay-Sachs and Allied Diseases Association, Inc.
     2001 Beacon St, Rm. 304
     Brookline, MA  02164
     [phone] or 277-3965

     National Retinitis Pigmentosa Foundation
     P.O. Box 5773
     Baltimore, MD  21208
     [phone]
     [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.,
eds.; McGraw-Hill, 1983.  Pp. 598-604.