Case report: segmental form of Hailey-Hailey disease

The article presents a clinical case of a rare segmental form of familial benign chronic pemphigus with a positive family history. Patient S., born in 2014, complained of unilateral eruptions in the area of the left retroauricular fold, left axilla, inguinal fold and labia majora on the left, plantar surface of the left foot. Eruptions were represented by erythematous foci, single blisters with serous contents, erosions, crusts. For the entire period, the patient was observed with the following diagnoses: microbial eczema, Sneddon-Wilkinson Disease, Inflammatory Linear Verrucose Epidermal Nevus. Due to the long-term relapsing course and ineffective therapy, additional examination methods were carried out – histological and genetic studies. Only after genetic testing, in which a heterozygous mutation of the ATP2C1 gene was revealed, and geneticist’s consultation, the final diagnosis was established – Hailey-Hailey Disease.
It is known, that the segmental form is formed as a result of mosaicism, which can be of two types. The term "mosaicism" refers to the presence in an organism of two or more genetically heterogeneous cell populations formed from a genetically homogeneous zygote. The formation of type 1 mosaicism is based on a de novo postzygotic mutation at an early stage of embryogenesis. In turn, type 2 mosaicism develops as a result of a postzygotic mutation against the background of an already existing prezygotic mutation. Determining the type of mosaicism by genetic testing will make it possible to assess the prognosis of the disease and the chance of transmitting this disease to offspring.