Small cell lung cancer (SCLC) accounts for about 15-20% of all lung cancer cases and is one of the most malignant tumors. In more than 90% of cases of SCLC, mutations of the TP53 gene are detected. The aim of our study was to analyze the structural changes in the 17p13 chromosomal region in patients with SCLC from the Republic of Bashkortostan. We used 70 lung tissue samples from patients with SCLC. The study was conducted using MLPA. Deletions and/or duplications in the coding regions of the TP53 gene were detected in 40% of the samples, including duplications of the first exon (23% of the samples) and deletions of the 4-6th and 11th exons of the TP53 gene (17% of the samples). Besides, the CHEK2 c.1100delC mutation was detected in four samples.