Goal. To determine the nucleotide protein-coding PERP gene sequence and assess the relation between the revealed mutations/polymorphisms and development of true acantholytic pemphigus as well as particular features of its course. Materials and methods. The protein-coding PERP gene DNA sequence was studied by the sequence analysis method in 18 patients with true acantholytic pemphigus. Results. Two polymorphisms were discovered in patients with true acantholytic pemphigus in Exon 3 of the PERP gene for the first time: rs648802 (non-synonymous) and rs648396 (synonymous). The incidence of wild type genotypes in the revealed polymorphisms (С/С genotype rs648802 and Т/Т genotype rs648396) in healthy volunteers reliably exceeded that in patients (p = 0.049). Patients with true acantholytic pemphigus are characterized by a higher incidence rate of mutant heterozygous genotypes С/G rs648802 and Т/C rs648396 (p = 0.09). Mutant heterozygous genotypes of the polymorphisms (G/G genotype rs648802 and С/С genotype rs648396) were revealed in patients with the earlier onset of the disease (41-60 years) (p = 0.025) more often while heterozygous genotypes (С/G genotype rs648802 and T/С genotype rs648396) were revealed when the disease developed at the age of 61 or older more often (p = 0.01). Conclusion. Identification of the polymorphous genotype by the sequence method or other molecular methods (e.g. PCR) can be used to forecast the terms when true acantholytic pemphigus can emerge in genetically inclined patients. However, it should be noted that it is necessary to specify the preliminary results obtained based on a greater sample of patients with true acantholytic pemphigus.