In the pathogenesis of atopic dermatitis (AD), the revealed changes in the epidermal barrier with a mutation in the filaggrin gene and the features of the immune response associated with polymorphism of interleukin genes play an important role. The work determined the presence of mutations in the filaggrin gene: R501X (rs61816761), 2282del4 (rs558269137), R2447X (rs138726443) and genetic polymorphism in the genes of cytokines IL-13 (rs20541), IL-4 (rs224s3250, VNTR29) IL-18 (rs187238) in 3 siblings with severe AD. The two patients within others had a mutation in the filaggrin R2447X gene (rs138726443); all children had polymorphism in the IL-4 and IL-13 genes, and one patient additionally had IL-18 gene polymorphism. Analysis of the course of blood pressure over 5 years (at the beginning of observation, the age of children was 9 years, 5 years and 2 years) showed that the clinical features of the disease did not depend on the identified genetic changes. The disease in children debuted after 3 years of age. The peak of disease activity occurred at the age of 5-9 years — a severe degree of the disease developed (SCORAD>50). The structure of the epidermis in the foci and outside the foci of blood pressure according to high-frequency ultrasound scanning of the skin did not depend on the presence of filaggrin gene mutations. All patients showed a quick positive response to proactive therapy but if the regimen of drug application was violated the relapse quickly occurred. The presented clinical case demonstrates the need to rethink the knowledge gained about the genetic predisposition to AD and the influence of various genes mutations and polymorphism on the development of the disease as applied to specific clinical situations.