The tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is a rare autosomal dominant disease associated with a mutation in the TNFRSF1A gene. It belongs to the group of monogenic autoinflammatory diseases (mAIDs) characterized by the repeated and prolonged episodes of fever, skin rashes, musculoskeletal, ophthalmic symptoms and an increase in the level of acute phase markers. The main targeted therapy is inhibitors of interleukin-1 (IL-1). The purpose of the study was to present the clinical and genetic characteristics of patients with TRAPS according to the data from the V.A. Nasonova Research Institute of Rheumatology (Moscow, Russia). The study included 28 patients from 2013 till 2021 with a clinical diagnosis of TRAPS from a selection of 162 (both pediatric and adult) patients with mAIDs: 17 females/11 males aged 2.5 to 65 years old (Me 9.0 y/o [7.9; 14.5]); 7 adults/21 children. All of them have underwent molecular genetic analysis for mutations in the TNFRSF1A gene. Results: the TRAPS was diagnosed in 28 (17.3%) among 162 patients with mAIDs. The age of onset ranged from 1 month till 28 years old (Me 4.0 y/o [1.0; 7.1]). Most patients fell ill prior to the age of 10 years old (89.3%), of which 8 (28.6%) before 1 year old, 7 (25%) from 1 to 5 years old, 1 (3.6%) from 5 to 10 years old, 10 (35.7%) from 10 to 18 years old and 2 (7.1%) from 21 to 28 years old. The duration of the disease and the delay in diagnosis at the time of inclusion ranged from 3 months till 59 years old. The diagnosis was made within the first year of illness in 4 (14.3%) of observed cases; within 1 to 10 years in 18 (64.3%); in 8 (28.6%) there was a delay in diagnosis of over 10 years; and in 4 (14.3%) the delay was more than 20 years of illness. The duration of attacks varied from 10 to 30 days, the intervals between the attacks ranged from 2 weeks till 6 months. The clinical manifestations were as follows: fever in 96.4% of cases, skin rashes in 71.4%, musculoskeletal symptoms in 18 (64.3%) cases, oligoarthritis in 9 (32.1%), polyarthritis in 2 (7.1% ), gastrointestinal manifestations in 18 (64.3%), lymphadenopathy of various groups in 10 (35.7%), ophthalmological manifestations in 8 (28.6%). The less often were the different nervous system manifestations, which accounted for 6% to 21% of cases, pharyngitis in 4 (14.3%) and stomatitis in 2 (7.1%). An increase in the sedimentation rate of erythrocytes was noted in 23 (82.1%), C-reactive protein in 20 (71.4%), leukocytosis in 11 (39.3%). The diagnosis in all patients was confirmed genetically. 10 patients had a low-penetrance mutation of р.Arg121Gln (р.Arg92Gln according to the old nomenclature). 5 familial cases were identified, the total number of sick family members was 12, from 2 to 4 in each family; 4 cases of amyloidosis (the all four were adults). Treatment: glucocorticoids in 19 (67.9%) cases, Cyclosporine A in 1, Colchicine in 5. 15 patients (53.6%) received genetically engineered biological preparations, the IL-1 (Canakinumab) was prescribed in 10 (35.7%) patients with the duration of admission from 1 to 9 years, Etanercept in 1, Adalimumab in 1 and Tocilizumab in 3. Conclusion: due to the similarity of clinical and laboratory symptoms with manifestations of rheumatic diseases, patients with TRAPS can be encountered in the rheumatologists’ practice. Most patients in the studied cohort had an early onset of the disease (prior to 10 years old), and the diagnosis delay of 10+ years was noted in 1/3 of patients. All patients had a specialized inflammatory phenotype coupled with genetic mutations. About half had required the appointment of biological drugs, IL-1 mainly. A complete response to the therapy in most patients and a good tolerability of treatment were noted, which allows the authors to consider this as the basis in the treatment and management of patients with TRAPS.