A case of type 1 segmental Darier disease showing widespread Blaschkoid skin lesions with p.P160L mutation in ATP2A2.

Darier disease is an autosomal dominant skin disease characterized by keratotic greasy papules and plaques, primarily in seborrheic and intertriginous areas. Darier disease is caused by mutations in ATP2A2 that encodes a sarco/endoplasmic reticulum Ca2(+) -ATPase (SERCA2), leading to compromised intercellular adhesion. The mosaicism caused by a postzygotic genetic change in ATP2A2 results in a segmental form of the disease. Lesions are basically limited to seborrheic and intertriginous areas in patients with type 1 segmental Darier disease which is caused by a somatic mutation in ATP2A2. In contrast, mild skin lesions are distributed to seborrheic and intertriginous areas, but severe lesions are distributed in a Blaschkoid manner in patients with type 2 segmental Darier disease which is caused by somatic mosaicism of a biallelic ATP2A2 mutation occurring in an ATP2A2 mutant heterozygote.