X-Linked Ectodermal Dysplasia

X-linked ectodermal dysplasia is a pathology characterized by hypotrichosis, absence of sweat glands and dental malformations.

Symptoms

Puppies born with X-linked ectodermal dysplasia have an absence of hair on approximately two-thirds of their body, a condition clinically known as hypotrichosis. In the affected areas of the skin, hair follicles are completely absent. In addition, these animals lack sweat glands and show dental anomalies, which may include malformed teeth or, in some cases, complete absence of teeth or oligodontia. Dry eyes, caused by a deficiency in tear production, may also be observed. Dogs with this genetic condition are more prone to respiratory infections.

Disease Management

Currently, there is no specific treatment available to combat hair loss caused by X-linked ectodermal dysplasia. However, your veterinarian may suggest the use of special shampoos or dietary supplements designed for skin care. In addition, it is important to constantly monitor your dog's health status to detect any respiratory infections early. In cases of severe dental malformations, surgical intervention may be necessary.

Genetic basis

This disease follows an X-linked recessive mode of inheritance. Recessive X-linked inheritance means that female dogs must receive two copies of the mutation or pathogenic variant (one from each parent) to develop the disease, whereas males need only one copy of the mutated gene or variant from the dam to develop the disease. Male dogs usually show symptoms of the disease. Each male puppy born to a mother carrying the mutation has a 50% chance of inheriting the mutation and thus the risk of developing the disease. Bitches that do not carry the mutation are not at increased risk of having affected puppies. Breeding between dogs carrying genetic variants that can cause disease, even if they do not show symptoms, is not recommended.

Technical report

X-linked ectodermal dysplasia is a rare genetic disease that has been identified in some dogs. This disease is caused by a defect in the EDA gene on the X chromosome and, as the name suggests, primarily affects structures derived from the ectoderm, one of the three germ layers of the embryo. The ectoderm is responsible for the development of various structures and organs, including skin, hair, nails, sweat glands, teeth and some parts of the nervous system. The EDA gene encodes for ectodysplasin and is involved in signaling pathways that occur during the development of ectoderm-derived organs. Ectodysplasin is thought to have some role in cell adhesion. The mutation in EDA we analyze here that causes ectodermal dysplasia in German shepherd dogs is c.910-1G>A.

Most affected breeds

Basset Hound
Belgian Shepherd
Bichon Frise
Cocker Spaniel
German Shepherd Dog
Labrador Retriever
Miniature Pinscher
Miniature Poodle
Mixed breed
Pekingese
Whippet
Yorkshire Terrier

Bibliography

Casal ML, Scheidt JL, Rhodes JL,et al. Mutation identification in a canine model of X-linked ectodermal dysplasia. Mamm Genome. 2005 Jul;16(7):524-31.

Lewis JR, Reiter AM, Mauldin EA,et al. Dental abnormalities associated with X-linked hypohidrotic ectodermal dysplasia in dogs. Orthod Craniofac Res. 2010 Feb;13(1):40-7.