Darier disease is a skin condition characterized by wart-like blemishes on the body. The blemishes are usually yellowish in color, hard to the touch, mildly greasy, and can emit a strong odor. The most common sites for blemishes are the scalp, forehead, upper arms, chest, back, knees, elbows, and behind the ear. The mucous membranes can also be affected, with blemishes on the roof of the mouth (palate), tongue, inside of the cheek, gums, and throat. Other features of Darier disease include nail abnormalities, such as red and white streaks in the nails with an irregular texture, and small pits in the palms of the hands and soles of the feet.

The wart-like blemishes characteristic of Darier disease usually appear in late childhood to early adulthood. The severity of the disease varies over time; affected people experience flare-ups alternating with periods when they have fewer blemishes. The appearance of the blemishes is influenced by environmental factors. Most people with Darier disease will develop more blemishes during the summertime when they are exposed to heat and humidity. UV light; minor injury or friction, such as rubbing or scratching; and ingestion of certain medications can also cause an increase in blemishes.

On occasion, people with Darier disease may have neurological disorders such as mild intellectual disability, epilepsy, and depression. Learning and behavior difficulties have also been reported in people with Darier disease. Researchers do not know if these conditions, which are common in the general population, are associated with the genetic changes that cause Darier disease, or if they are coincidental. Some researchers believe that behavioral problems might be linked to the social stigma experienced by people with numerous skin blemishes.

A form of Darier disease known as the linear or segmental form is characterized by blemishes on localized areas of the skin. The blemishes are not as widespread as they are in typical Darier disease. Some people with the linear form of this condition have the nail abnormalities that are seen in people with classic Darier disease, but these abnormalities occur only on one side of the body.

Normal Function

The ATP2A2 gene provides instructions for making an enzyme called sarco(endo)plasmic reticulum calcium-ATPase 2 (SERCA2). This enzyme belongs to a family of ATPase enzymes that helps control the level of positively charged calcium atoms (calcium ions) inside cells. Within the cell, SERCA2 is found in the endoplasmic reticulum and a related structure in muscle cells called the sarcoplasmic reticulum. The endoplasmic reticulum is a structure inside the cell that is involved in protein processing and transport. The sarcoplasmic reticulum assists with muscle contraction and relaxation by releasing and storing calcium ions. Calcium ions act as signals for a large number of activities that are important for the normal development and function of cells. SERCA2 allows calcium ions to pass into and out of the cell in response to cell signals.

Health Conditions Related to Genetic Changes

Darier disease

More than 130 mutations in the ATP2A2 gene have been found to cause Darier disease. Most of these mutations change a single protein building block (amino acid) in the SERCA2 enzyme. All mutations cause the production of a nonfunctional SERCA2 enzyme or cause no SERCA2 to be produced from one copy of the gene. Cells with only one functional copy of the ATP2A2 gene produce half the normal amount of SERCA2 protein. It is thought that insufficient amounts of SERCA2 combined with outside factors such as heat and minor injury cause the signs and symptoms of Darier disease.

Other Names for This Gene

• AT2A2_HUMAN
• ATP2B
• ATPase, Ca++ dependent, slow-twitch, cardiac muscle-2
• ATPase, Ca++ transporting, cardiac muscle, slow twitch 2
• calcium-transporting ATPase sarcoplasmic reticulum type, slow twitch skeletal muscle isoform
• sarcoplasmic reticulum Ca(2+)-ATPase 2
• sarcoplasmic/endoplasmic reticulum calcium ATPase 2
• SERCA2
• SR Ca(2+)-ATPase 2

Genomic Location

Darier disease is usually diagnosed by the appearance of the skin and the family history. It may be mistaken for other skin conditions. The diagnosis may require a skin biopsy. Genetic testing to identify a mutation in the ATP2A2 gene can be used to confirm the diagnosis.