Hypohirotic ectodermal dysplasia, X-linked (XLHED) is a rare genetic condition linked to the X-chromosome. XHLED affects ectodermal tissues including the nervous system, tooth enamel, and outer skin layer called the epidermis. It is the most common of the many forms of ectodermal dysplasia. It is characterized by the inability to sweat, sparse body and scalp hair, and missing and/or pointed teeth. Other symptoms include dry mouth and nostrils, dry or rough skin, bad smelling discharge from the nose, and a greater risk of respiratory infections and asthma. Due to the lack of fully developed sweat glands, individuals with this condition cannot properly cool their body temperature through sweating and can easily become overheated. Persons with XLHED share similar facial characteristics such as thin, wrinkled and dark skin beneath the eyes, a shallow or depressed nasal bridge and small jaw. There is currently no cure for the condition, but there are treatments. Due to the lack of sweat glands, individuals with XLHED often wear cooling vests, drink cool fluids regularly, and mist themselves with water. They are encouraged to avoid activities that may cause them to overheat such as sports. Creams and lotions may be used to treat the dry skin. Research is being conducted and there are hopes of potential treatments that will alter the symptoms of XLHED and improve the lives of those affected.
XLHED is caused by an error in the EDA gene on the X-chromosome. Because it is X-linked, it mostly occurs in males. However, female carriers may present with mild to severe symptoms. In some cases, genetic testing is available. A genetic counselor can help in understanding the genetic basis and recurrence risks of XLHED. Talk to your doctor for the most up to date treatments for XLHED if you or your child is affected. Support groups can also be a good source of information and can help you connect with other families affected with XHLED.