CD-ROM Today 1996 January/CD-ROM Today 1996 January.iso/dp/0385/03859.txt

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$Unique_ID{BRK03859}
$Pretitle{}
$Title{Ichthyosis}
$Subject{Ichthyosis Disorder of Cornification DOC Ichthyosis Congenita
(Collodion Baby; Congenital Ichthyosiform Erythroderma; Xeroderma;
Desquamation of Newborn) X-Linked Ichthyosis Ichthyosis Vulgaris;  X-Linked
Ichthyosis;  Epidermolytic Hyperkeratosis; Lamellar Recessive Ichthyosis;
Ichthyosis Congenita;  Lamellar Dominant Ichthyosis;  Harlequin Type
Ichthyosis;  Ichthyosis Hystrix, Curth-Macklin Type;  Netherton Syndrome;
Sjogren-Larsson Syndrome;  Refsum Syndrome; Chanarin-Dorfman Syndrome;
Multiple Sulfatase Deficiency;  Tay Syndrome; Keratitis Ichthyosis Deafness
Syndrome (KID Syndrome); CHILD Syndrome; Conradi-Hunermann Syndrome;
Erythrokeratodermia Variabilis; Erythrokeratolysis Hiemalis;
Erythrokeratodermia Progressiva Symmetrica; Peeling Skin Syndrome;  Darier
Disease (Keratosis Follicularis);  Giroux-Barbeau Syndrome;  Keratosis
Follicularis Spinulosa Decalvans. }
$Volume{}
$Log{}

Copyright (C) 1988, 1989, 1992, 1993 National Organization for Rare
Disorders, Inc.

542:
Ichthyosis

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

Synonyms

     Disorder of Cornification
     DOC

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

     Ichthyosis Congenita (Collodion Baby; Congenital Ichthyosiform
     Erythroderma; Xeroderma; Desquamation of Newborn)
     X-Linked Ichthyosis

The 24 known forms of Ichthyosis are:

Ichthyosis Vulgaris;  X-Linked Ichthyosis;  Epidermolytic Hyperkeratosis;
Lamellar Recessive Ichthyosis;  Ichthyosis Congenita;  Lamellar Dominant
Ichthyosis;  Harlequin Type Ichthyosis;  Ichthyosis Hystrix, Curth-Macklin
Type;  Netherton Syndrome;  Sjogren-Larsson Syndrome;  Refsum Syndrome;
Chanarin-Dorfman Syndrome;  Multiple Sulfatase Deficiency;  Tay Syndrome;
Keratitis Ichthyosis Deafness Syndrome (KID Syndrome);  CHILD Syndrome;
Conradi-Hunermann Syndrome;  Erythrokeratodermia Variabilis;
Erythrokeratolysis Hiemalis;  Erythrokeratodermia Progressiva Symmetrica;
Peeling Skin Syndrome;  Darier Disease (Keratosis Follicularis);  Giroux-
Barbeau Syndrome;  Keratosis Follicularis Spinulosa Decalvans.

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.


Ichthyosis is a general term describing a group of skin disorders that
are characterized by an excessive accumulation of large amounts of dead skin
cells (squames) in the top layer of the skin.  The conversion of an
abnormally large number of skin cells into squamous cells is thought to be
caused by a defect in the metabolism of skin cells known as "corneocytes", or
of the fat-rich matrix around these cells.  The cells can be thought of as
bricks, while the matrix would be the mortar holding these cells together.
In general, all forms of Ichthyosis cause dry scaly skin.

Symptoms

Ichthyosis is characterized by scaly and dry skin usually over large areas of
the body.  The skin also itches (pruritus) and is red (erythematous).  A baby
born with some forms of the disorder, may be born covered with a starchlike
(collodion) membrane.  Remissions of symptoms may occur and symptoms may
vary, ranging from mild to severe.

Causes

Most known forms of Ichthyosis are hereditary disorders.  Some are caused by
dominant genes, some are recessive.

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 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.

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.

X-linked recessive disorders are conditions which are coded on the X
chromosome.  Females have two X chromosomes, but males have one X chromosome
and one Y chromosome.  Therefore in females, disease traits on the X
chromosome can be masked by the normal gene on the other X chromosome.  Since
males have only one X chromosome, if they inherit a gene for a disease
present on the X, it will be expressed.  Men with X-linked disorders transmit
the gene to all their daughters, who are carriers, but never to their sons.
Women who are carriers of an X-linked disorder have a fifty percent risk of
transmitting the carrier condition to their daughters, and a fifty percent
risk of transmitting the disease to their sons.

In X-linked dominant disorders the female with only one X chromosome
affected will develop the disease.  However the affected male always has a
more severe condition.  Sometimes affected males die before birth so that
only female patients survive.

Affected Population

Most known forms of Ichthyosis are present at birth.  Except for X-Linked
Ichthyosis (which affects only males), most forms of ichthyosis affect males
and females in equal numbers.

Related Disorders

The following disorders are forms of Ichthyosis.  Comparisons can be useful
for a differential diagnosis:

Ichthyosis Congenita (Collodion Baby; Congenital Ichthyosiform
Erythroderma; Xeroderma; Desquamation of Newborn) is characterized by
generalized, abnormally red, dry and rough skin, with large, coarse scales.
Itchiness (pruritus) usually also develops.  Skin on the palms of the hands
and soles of the feet is abnormally thick.  (For more information, choose
"Ichthyosis Congenita" as your search term in the Rare Disease Database.)

X-Linked Ichthyosis is an inherited skin disorder that affects males.  It
is caused by a deficiency of the enzyme steroid sulfatase.  This enzyme
deficiency leads to biochemical alterations in steroid hormone metabolism.
Cholesterol sulfate may accumulate in the blood and skin.  (For more
information, choose "X-Linked Ichthyosis" as your search term in the Rare
Disease Database.)

Other forms of Ichthyosis include:

Ichthyosis Vulgaris;  Epidermolytic Hyperkeratosis;  Lamellar Recessive
Ichthyosis;  Lamellar Dominant Ichthyosis;  Harlequin Type Ichthyosis;
Ichthyosis Hystrix, Curth-Macklin Type;  Netherton Syndrome;  Sjogren-Larsson
Syndrome;  Refsum Syndrome;  Chanarin-Dorfman Syndrome;  Multiple Sulfatase
Deficiency;  Tay Syndrome;  Keratitis Ichthyosis Deafness Syndrome (KID
Syndrome);  CHILD Syndrome;  Conradi-Hunermann Syndrome;  Erythrokeratodermia
Variabilis;  Erythrokeratolysis Hiemalis;  Erythrokeratodermia Progressiva
Symmetrica;  Peeling Skin Syndrome;  Darier Disease (Keratosis Follicularis);
Giroux-Barbeau Syndrome;  Keratosis Follicularis Spinulosa Decalvans.
(Search under each name for more information on that disorder in the Rare
Disease Database.)

Therapies:  Standard

The dry scaly skin of Ichthyosis is treated by applying skin softening
(emollient) ointments, preferably plain petroleum jelly.  This can be
especially effective after bathing while the skin is still moist.  Salicylic
acid gel is another particularly effective ointment.  The skin should be
covered at night with an airtight, waterproof dressing when this ointment is
used.  Lactate lotion can also be an effective treatment for this disorder.

Drugs derived from Vitamin A (retinoids) such as tretinoin, motretinide,
and etretinate are often effective against symptoms of Ichthyosis, but can
cause toxic effects on the bones in some cases.  A synthetic derivative of
Vitamin A, isotretinoin, when taken by pregnant women, can cause severe birth
defects to the fetus.  These Vitamin A compounds have not yet been approved
by the Food and Drug Administration (FDA) for treatment of Ichthyosis, and
should be avoided by women of child-bearing age.

Therapies:  Investigational

The National Institute of Arthritis, Musculoskeletal and Skin Diseases is
looking for patients with various kinds of Ichthyosis willing to participate
in research aimed at mapping the genes responsible for their disorder.
Interested persons may contact:

     Dr. Sherri Bale
     National Institute of Arthritis, Musculoskeletal and Skin Diseases
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]

The orphan product Monolaurin (Glylorin) is being tested for treatment of
Ichthyosis.  The product is manufactured by:

     Cellegy Pharmaceuticals, Inc.
     371 Bel Marin Keys, Suite 210
     Novato, CA  94949

This disease entry is based upon medical information available through
May 1993.  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 Ichthyosis, please contact:

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

     Foundation for Ichthyosis and Related Skin Types, Inc. (F.I.R.S.T.)
     P.O. Box 20921
     Raleigh, NC  27619-0921
     [phone]
     [phone]

     The National Arthritis, Musculoskeletal and Skin Diseases (NIAMS)
Information Clearinghouse
     Box AMS
     Bethesda, MD  20892
     [phone]

For information on genetics and genetic counseling:

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

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

References

GENETICALLY TRANSMITTED, GENERALIZED DISORDERS OF CORNIFICATION.  THE
ICHTHYOSES:  M.L. Williams, et al.;  Dermatol Clin (January 1987:  issue
5(1)).  Pp. 155-178.

THERAPEUTIC ACTIVITY OF LACTATE 12% LOTION IN THE TREATMENT OF
ICHTHYOSIS.  ACTIVE VERSUS VEHICLE AND ACTIVE VERSUS A PETROLEUM CREAM:  M.
Buxman, et al.; Journal Am Acad Dermatol (December 1986:  issue 15(6)).  Pp.
1253-1258.

THE METABOLIC BASIS OF INHERITED DISEASE, 5th ed.:  John B. Stanbury, et
al., eds.; McGraw Hill, 1983.  Pp. 1027-1039.