What is ED?
What exactly is ED? | What causes ED? | What is an Ectodermal structure?
What exactly is ED?
Ectodermal Dysplasia (ED) is not a single disorder, but a group of closely related conditions of which more than 150 different syndromes have been identified. The Ectodermal Dysplasias (EDs) are genetic disorders affecting the development or function of the teeth, hair, nails and sweat glands. Depending on the particular syndrome ED can also affect the skin, the lens or retina of the eye, parts of the inner ear, the development of fingers and toes, the nerves and other parts of the body.
Each syndrome usually involves a different combination of symptoms, which can range from mild to severe, such as:
- Absence or abnormality of hair growth
- Absence or malformation of some or all teeth
- Inability to perspire, which causes overheating
- Impairment or loss of hearing or vision
- 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
- Irregular skin pigmentation.
In addition to the above they may have:
- Sensitivity to light
- Respiratory problems
- A lack of breast development
- A host of other challenges
Individuals affected by ED face a lifetime of special needs which may include:
The inheritance patterns are variable according to the specific type of ED. Patterns include:
- Dentures at a young age with frequent adjustments and replacements
- Special diets to meet dental/nutritional needs
- Air conditioned environments
- Wigs to conceal hair and scalp conditions
- Carrier identification testing
Protective devices from direct sunlight
- Osseointegrated dental implants
- Respiratory therapies
- spontaneous mutations
- autosomal dominant
- autosomal recessive
- X-linked dominant
- X-linked recessive
When questions of a diagnosis exist, the expertise of a geneticist or other doctor with experience with the EDs is strongly recommended.
It is important to remember that not all individuals affected by the EDs will have physical features that fit the description of a specific syndrome. There may be a great deal of variation in the physical appearance of the same type of ED from one affected person to the next. It is also conceivable for a person to have a type of ED that has not been described yet. Nonetheless, the EDs share certain features, an understanding of which makes it possible to appreciate the ramifications for most affected individuals and allows everyone involved to respond appropriately to the individual's needs.
What causes ED?
Ectodermal Dysplasias are caused by altered genes. The altered genes may be inherited or normal genes may become defective (mutate) at the time of conception. The chances for parents to have affected children depend on the type of ED that exists in the family.
It is important to remember that a person cannot choose or modify the genes that he or she has, and that events of pregnancy do not change the genes. Thus, parents who have a child with ED should not think that they did anything to cause the defective gene and should not blame themselves for its existence. Genetic counseling is available for families.
One common type of ED affects males more than females this is the X-linked type of hypohidrotic ED, other types can affect males or females equally and may be inherited in different ways.
Pre-natal diagnosis is available for some families with X-linked hypohidrotic ectodermal dysplasia, through the use of DNA probes. This is not possible for all families.
What is an Ectodermal Structure?
Before a developing baby is large enough to be seen, a layer of cells covers the outside of the body. This surface layer of cells is called the ectoderm, and from it develops the skin, hair, nails, teeth, nerve cells, sweat glands, parts of the eye and ear, and parts of some other organs. Each of the listed parts of the body is then called an ectodermal structure.