Hypohidrotic ectodermal dysplasia is one of more than 100 types of ectodermal dysplasia. Starting before birth, these disorders result in the abnormal development of ectodermal tissues, particularly the skin, hair, nails, teeth, and sweat glands.

Hypohidrotic ectodermal dysplasia is a genetic condition that can result from mutations in one of several genes. These include EDA, EDAR, EDARADD, and WNT10A. EDA gene mutations are the most common cause of the disorder, accounting for more than half of all cases. EDAR, EDARADD, and WNT10A gene mutations each account for a smaller percentage of cases. In about 10 percent of people with hypohidrotic ectodermal dysplasia, the genetic cause is unknown.

Hypohidrotic ectodermal dysplasia is the most common form of ectodermal dysplasia. It is estimated to occur in 1 in 20,000 newborns worldwide.

Hypohidrotic ectodermal dysplasia has several different inheritance patterns. Most cases are inherited in an X-linked pattern and are caused by mutations in the EDA gene. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females, who have two copies of the X chromosome, one altered copy of the gene in each cell often leads to less severe features of the condition. Signs and symptoms can include a few missing or abnormal teeth, sparse hair, and mild problems with sweat gland function. However, some females with one copy of the mutated gene have more severe features of this disorder.

Published Date: November 01, 2018Published By: National Institutes of Health