ABSTRACT Despite the sporadic incidence of leprosy in Russia, new cases may be not only due to increase in migration stream from highly endemic countries, but also due to the development of the disease in persons, who have long contact with leprosy patients. The likelihood of leprosy is directly related to the duration and closeness of contact with the source of the disease. The risk of infection is higher for people who cohabitate with leprosy patients for a long time as compared to the general population. Among family members of leprosy patients, blood relatives are more likely to be infected. The article describes the case of the development of lepromatous leprosy in a female, whose parents were leprosy patients. Bacterioscopic and histological examination of the patient showed acid-fast mycobacteria in the biopsy sample and skin scarifications (BIN = 3.67). Identification of Mycobacterium leprae was carried out by polymerase chain reaction (PCR) based on DNA-STRIP hybridization technique using GenoType Leprae DR primers (Hain Lifescience, Germany). M. leprae sensitive to the major antileprotics (rifampicin, ofloxacin, dapsone) were detected in all samples. Serologic examination of blood serum by ELISA for the presence of IgM, IgG antibodies to specific antigen M. leprae (DIS-BSA) showed that optical density of both IgM and IgG antibodies exceeded the limits. Additionally, HLA-genotyping of both the patient and her mother showed HLA-DRB1-*15-DQA1-*0102 -DQB1-*0602/08 haplotype, which was previously identified as a marker predisposing to leprosy in the Russian population. Thus, implementation of molecular genetic, serological and immunogenetic methods along with the standard bacterioscopic and histological methods in examination of leprosy patients and contact persons facilitates verification of the diagnosis of leprosy at the early stages of the disease.