Analysis of the pathogenic <i>CYP21A2</i> gene variants in patients with clinical, biochemical and combined manifestations of hyperandrogenism

Abstract

BACKGROUND: The association of heterozygous carriage of pathogenic variants in the CYP21A2 gene with various manifestations of hyperandrogenism remains poorly understood to date.
 AIM: The aim of this study was to analyze the relationship between the carriage of pathogenic variants in the CYP21A2 gene in women and various manifestations of hyperandrogenism.
 MATERIALS AND METHODS: Clinical description, hormonal testing and molecular genetic analysis of the CYP21A2 gene were performed in 97 women with clinical, biochemical and combined manifestations of hyperandrogenism and in 46 people in the control group. The mean age of the patients was 27.3 0.6 years. Levels of 17-hydroxyprogesterone, dehydroepiandrosterone sulfate and androstenedione were measured in the blood serum of the study participants. To identify pathogenic variants in the CYP21A2 gene, we used next generation sequencing, restriction fragment length polymorphism analysis, real-time polymerase chain reaction, and multiplex ligation-dependent probe amplification analysis. A statistical analysis of the frequency of pathogenic CYP21A2 gene variants in the study groups and hormone levels in different study subgroups was carried out.
 RESULTS: In patients with hirsutism, acne, menstrual irregularity, miscarriage and infertility, pathogenic variants in the CYP21A2 gene were identified in 31% (30/97) of cases in the heterozygous state and in 6% (5/97) of cases in the homozygous state. The frequency of these variants (in the heterozygous state only) was significantly higher 6.5% (3/46) of cases, when compared to the control group (p 0.0001). The identified pathogenic variants included both single nucleotide substitutions such as P31L (n = 1), I2splice (n = 1), V282L (n = 15), I173N (n = 3), Q319X (n = 8), R357W (n = 1), P454S (n = 1), and P483S (n = 1) and deletions of various lengths (n = 10). We found no significant difference in the levels of dehydroepiandrosterone sulfate and androstenedione between heterozygous carriers and the control group and between heterozygous carriers and patients with the wild type CYP21A2 gene (p 0.05), while 17-hydroxyprogesterone level in the group of patients with heterozygous changes was higher, when compared to the control group (p 0.001).
 CONCLUSIONS: Heterozygous carriage of pathogenic variants in the CYP21A2 gene is associated with manifestations of hyperandrogenism. However, further study of the mechanisms underlying this association is required.