Atopic dermatitis (AD) is a widespread multifactorial genetically determined inflammatory skin disease caused by, among other causes, impaired functions of the epidermal barrier. Loss-of-function mutations of the filaggrin gene (important component of the natural moisturizing factor system) that arrest production of the full-fledged precursor protein are associated with AD. This work investigated the frequency of the 2282delACTG (rs558269137), R501X (rs61816761), S3247X (rs150597413), R2447X (rs138726443) loss-of-function mutations of the filaggrin gene in adult European patients with moderate to severe AD. The study involved 99 adult patients of both sexes aged 18-68 years. The mutations were identified with the help of the purpose-developed method of multiplex analysis of four single nucleotide polymorphisms that relies on the SNaPshot technique (minisequencing). The incidence of loss-of-function mutation of filaggrin 2282delACTG was 5.3%, that of R501X - 0.5%, R2447X - 1%. No S3247X mutation was detected in the sample. Collation of the results with Russian and European samples revealed a comparable level of the analyzed filaggrin gene mutations in adult patients with AD from different regions of the Russian Federation.