The correct answer is B. ATP2C1

The disease shown in the image is Hailey-Hailey disease (familial benign pemphigus) which is an autosomal dominant genodermatosis, caused by a mutation in ATP2C1, encoding a calcium pump protein related to SERCA2. It is characterized by recurrent vesicles and erosions, which most commonly appear on the sides and back of the neck, in the axillae, in the groin, and in the perianal regions. The disorder is not seen before puberty and usually has its onset in the late teens or early second decade of life. In the intertriginous area, lesions tend to form erythematous plaques with dry crusting and soft, flat, and moist granular vegetations. Burning or pruritus is common, and, particularly in the intertriginous areas, lesions tend to become irritating, painful, and exceedingly uncomfortable.

Darier’s disease is associated with a mutation in ATP2A2 gene. Junctional epidermolysis bullosa is caused by defects with collagen type 17. Bullous pemphigoid (BP) is a blistering skin disease in which autoantibodies develop to hemidesmosomal components of the epidermal basement membrane including two major antigenic proteins of the 230-kD antigent (BPAG1) and the 180-kD antigent (BPAG2).

References: Chiaravalloti A, Payette M. Hailey-Hailey disease and review of management. J Drugs Dermatol. 2014;13(10):1254-1257. Deng H, Xiao H. The role of the ATP2C1 gene in Hailey-Hailey disease. Cell Mol Life Sci. 2017;74(20):3687-3696. doi:10.1007/s00018-017-2544-7