Ectodermal Dysplasia

Background

Ectodermal dysplasia (ED) is not a single disorder, but a group of closely-related conditions of which more than 160 different syndromes have been identified. They are genetic conditions affecting the development or function of the teeth, hair, nails and/or sweat glands. Some of these particular ED syndromes can also affect the skin more generally, the lens or retina of the eye, parts of the inner ear, the development of hands and feet, the mouth and palate, the nerves and other parts of the body.

Credits

Last updated July 2018 by Professor A Clarke, Professor in Clinical Genetics, Institute of Cancer & Genetics, School of Medicine, Cardiff University, Wales, UK.

Although great care has been taken in the compilation and preparation of all entries to ensure accuracy, we cannot accept responsibility for any errors or omissions. Any medical information is provided for education/information purposes and is not designed to replace medical advice by a qualified medical professional.

What are the symptoms?

ED can cause problems with:

  • absence or abnormality of hair growth
  • absence or malformation of some or all teeth
  • failure to develop sweat glands that results in the inability to sweat, which causes overheating
  • failure to develop other glands that are closely related to the sweat glands (such as the salivary and lacrimal glands and the breasts)
  • dryness of the eyes, leading to sore, red eyes, frequent infections, damage to the cornea and cataracts
  • reduced mucus in the nose and airways, leading to crusting and bleeding from the nose and chest infections
  • frequent infections due to immune system deficiencies or, in some cases, the inability of cracked or eroded skin to keep out disease-causing bacteria
  • absence or malformation of some fingers or toes
  • cleft lip and/or palate
  • skin pigmentation, often in irregular patches

In addition to the above, there may be problems with:

  • sensitivity to light
  • asthma, eczema and food allergies
  • a lack of breast development (in females)
  • impairment or loss of hearing or vision
  • constipation.

What are the causes?

A number of genes have been identified, with the one most commonly involved being on the X chromosome. Alterations in this gene and a few others (especially the EDAR gene on chromosome 2) cause hypohidrotic ED (in which the secretions from sweat glands and other glands are reduced or absent). Alterations in a different gene (the p63 gene) can affect the development of the hands, feet and palate as well as affecting the eyes and causing other features of ED. There are many other genes that may be involved. In most cases, each affected patient or family has a specific gene alteration in one particular gene.

How is it diagnosed?

In some cases, ED is apparent at birth from the clinical features present. In other cases, it may become evident when teeth fail to develop normally or other features are noted. Testing to identify the particular gene alteration in each patient is often feasible.

How is it treated?

Treatment for ED will involve supporting particular difficulties experienced as a result of the condition.

Individuals affected by ED may need support with:

  • feeding problems, especially in infancy and early childhood
  • dentures at a young age, with frequent adjustments and replacements
  • dental implants (artificial tooth root replacement) when older
  • advice or equipment (e.g. fans or air conditioning) to help with cooling in hot weather or in school classrooms
  • creams to keep the skin soft and to treat eczema
  • special diets to meet dental/nutritional needs or control allergies
  • wigs to conceal hair and scalp conditions (although wigs may be unhelpful for some, especially when reduced sweating is a problem).
  • devices or creams to protect from sunlight
  • eye drops to prevent damage from dryness of the cornea
  • therapies to help with breathing, such as treatments for recurrent chest infections and/or asthma.

Specialist assessment and treatment by an ophthalmologist for other eye problems may be required.

Inheritance patterns and prenatal diagnosis

Inheritance patterns
These are variable according to the specific type of ED. Patterns include autosomal dominant, autosomal recessive and X-linked. Cases can arise as isolated (sporadic) cases within a family, when the mode of inheritance may be unclear. Genetic counselling is available for families that are affected.

Prenatal diagnosis
This is available for some types of ED, but is not possible for all families. If the mutation responsible for the ED in a family is known, then Preimplantation Genetic Diagnosis (PGD: genetic testing of an IVF conception) may be available. Both prenatal diagnosis and PGD must be arranged well in advance of a pregnancy.

Is there support?

Ectodermal Dysplasia Society

Tel: 01242 261332
Email: info@edsociety.co.uk
Website: www.edsociety.co.uk

The Society is a Registered Charity in England and Wales No. 1089135. It provides information, advice and support to those affected by an ectodermal dysplasia, promotes the education of medical professionals and general public, supports research, encourages a network for mutual support and produces a newsletter. The Society has a medical advisory board.

Group details last updated August 2021.

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