$Unique_ID{BRK03869} $Pretitle{} $Title{Ichthyosis, Harlequin Type} $Subject{Ichthyosis, Harlequin Type Harlequin Fetus DOC 6 (Harlequin Type) Disorder of Cornification 6 (Harlequin Type) Ichthyosis Harlequin Type Ichthyosis Congenita, Harlequin Fetus Type Ichthyosis (Disorders of Cornification)} $Volume{} $Log{} Copyright (C) 1988, 1989, 1991, 1992, 1993 National Organization for Rare Disorders, Inc. 546: Ichthyosis, Harlequin Type ** IMPORTANT ** It is possible the main title of the article (Harlequin Type 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 Harlequin Fetus DOC 6 (Harlequin Type) Disorder of Cornification 6 (Harlequin Type) Ichthyosis Harlequin Type Ichthyosis Congenita, Harlequin Fetus Type Information on the following disorders can be found in the Related Disorders section of this report: Ichthyosis (Disorders of Cornification) 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. Harlequin Type Ichthyosis is a rare genetic skin disorder characterized by massive, thick skin plates that usually produce distorted facial features and often deformities in other parts of the body. At birth the chest and abdomen of patients are usually severely constricted. This makes breathing and eating difficult. The skin symptoms can be somewhat controlled with treatment. Symptoms At birth, babies with Harlequin Type Ichthyosis have massive, thick scales on the skin. An abnormally large amount of dead skin cells (squames) accumulates in the top layer of the skin. The conversion of an abnormally large number of epidermal cells is thought to be caused by a defect in the metabolism of the 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. The scaly plates formed by these dead skin cells cause the dermatological symptoms. The chest and abdomen of these infants are severely constricted at birth. This makes breathing and eating difficult. Causes Harlequin Type Ichthyosis is a hereditary disorder transmitted through 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.) Affected Population Harlequin Type Ichthyosis is a rare skin condition that affects infants before birth. Males and females are affected in equal numbers. It affects one in 500,000 persons or two per million. Harlequin type Ichthyosis affects about 500 persons and occurs in seven births annually in the United States. Related Disorders Symptoms of the following disorders may be similar to those of Harlequin Type Ichthyosis. Inversion of an abnormally large number of epidermal cells into squamous cells is thought to be caused by a defect in the metabolism of the skin cells known as "corneocytes" or of the fat-rich matrix around these cells. The cells can be comparumulation of large amounts of dead cells (squames) in the top layer of the skin. Ichthyosis Congenita (Collodion Baby; Congenital Ichthyosiform Erythroderma; Xeroderma; Desquamation of Newborn) is an inherited skin disorder. It 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 caused by a deficiency in 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 Sjogren-Larsson Syndrome, Netherton Syndrome, Ichthyosis Hystrix, Lamellar Ichthyosis, Refsum Syndrome, Darier Disease, Conradi-Hunermann Syndrome, Chanarin-Dorfman Syndrome, Epidermolytic Hyperkeratosis, etc. (Search under each name for more information on that disorder in the Rare Disease Database.) Therapies: Standard Harlequin Type Ichthyosis can be diagnosed before birth by removing a tiny skin sample from the fetus and examining this for abnormal cells. This test is called fetoscopy. The skin symptoms of Harlequin Type Ichthyosis are 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. Other treatment is symptomatic and supportive. Therapies: Investigational Drugs derived from Vitamin A (retinoids) such as tretinoin, motretinide, and etretinate are often effective against the dermatologic symptoms of Harlequin Type 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 for treatment of Ichthyosis. 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 (301) 402-2679 The orphan product Monolaurin (Glylorin) is being tested for treatment of Harlequin Type 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 Harlequin Type Ichthyosis, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 Foundation for Ichthyosis and Related Skin Types, Inc. (F.I.R.S.T.) P.O. Box 20921 Raleigh, NC 27619-0921 (919) 782-5728 (800) 545-3286 The National Arthritis and Musculoskeletal and Skin Diseases (NIAMS) Information Clearinghouse Box AMS Bethesda, MD 20892 (301) 495-4484 For genetic information and genetic counseling referrals, 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 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. MENDELIAN INHERITANCE IN MAN, 7th ed.: Victor A. McKusick; Johns Hopkins University Press, 1986. P. 1059.