Hypohidrotic Ectodermal Dysplasia
National Organization for Rare Disorders, Inc.
It is possible that the main title of the report Hypohidrotic Ectodermal Dysplasia is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
Hypohidrotic ectodermal dysplasia (HED) is a rare inherited multisystem disorder that belongs to the group of diseases known as ectodermal dysplasias. Ectodermal dysplasias typically affect the hair, teeth, nails, sweat glands, and/or skin. HED is primarily characterized by partial or complete absence of certain sweat glands (eccrine glands), causing lack of or diminished sweating (anhidrosis or hypohidrosis), heat intolerance, and fever; abnormally sparse hair (hypotrichosis), and absence (hypodontia) and/or malformation of certain teeth. Many individuals with HED also have characteristic facial abnormalities including a prominent forehead, a sunken nasal bridge (so-called "saddle nose"), unusually thick lips, and/or a large chin. The skin on most of the body may be abnormally thin, dry, and soft with an abnormal lack of pigmentation (hypopigmentation). However, the skin around the eyes (periorbital) may be darkly pigmented (hyperpigmentation) and finely wrinkled, appearing prematurely aged. In many cases, affected infants and children may also exhibit underdevelopment (hypoplasia) or absence (aplasia) of mucous glands within the respiratory and gastrointestinal (GI) tracts and, in some cases, decreased function of certain components of the immune system (e.g., depressed lymphocyte function, and rarely cellular immune hypofunction), potentially causing an increased susceptibility to certain infections and/or allergic conditions. Many affected infants and children experience recurrent attacks of wheezing and breathlessness (asthma), respiratory infections; chronic inflammation of the nasal passages (atrophic rhinitis), scaling, itchy (pruritic) skin rashes (eczema), and/or other findings.
HED is usually inherited as an X-linked recessive genetic trait and is caused by a mutation in the ectodysplasin-A (EDA) gene; in such cases, the disorder is fully expressed in males only. However, females who carry a single copy of the disease gene (heterozygote carriers) may exhibit some of the symptoms and findings associated with the disorder. These may include absence and/or malformation of certain teeth, sparse hair, and/or reduced sweating. HED can also be inherited as an autosomal dominant or autosomal recessive genetic trait, caused by mutations in the EDAR or EDARADD genes. In such cases, the disorder is fully expressed in both males and females.
National Foundation for Ectodermal Dysplasias
6 Executive Drive
Fairview Hiights, IL 62208-1360
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases
One AMS Circle
Bethesda, MD 20892-3675
NIH/National Institute of Dental and Craniofacial Research
Building 31, Room 2C39
31 Center Drive, MSC 2290
Bethesda, MD 20892
Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
PO Box 241956
Los Angeles, CA 90024
Ectodermal Dysplasia Society
Unit 1 Maida Vale Business Centre
England, GL53 7ER
For a Complete Report
This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".
The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.
It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report
This disease entry is based upon medical information available through the date at the end of the topic. 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.
For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email firstname.lastname@example.org
Last Updated: 4/2/2014
Copyright 1998, 2002, 2014 National Organization for Rare Disorders, Inc.