Introduction:
Uterine leiomyomas (UL) are highly prevalent benign smooth muscle tumors, seen in approximately 70% of women. These hormone re- sponsive tumors are also known to secrete prolactin (PRL), a hormone of the anterior pituitary gland. Elevated levels of serum prolactin are a com- mon clinical finding in different gynecological pathologies including UL. However, the underlying causes for this elevation are not yet clear. Therefore, the main objective of this study is to measure the serum PRL in UL patients and also to investigate its molecular connection with coding region somatic mutations of the PRL gene.

Material and methods:
The serum PRL levels of UL patients were measured through the ELISA method. The coding region PRL gene mutations in UL and corresponding myometrium tissues were screened through the Sanger sequencing method.

Results:
Uterine leiomyoma patients demonstrated significant elevation of the PRL hormone level in serum samples (p ≤ 0.01). No somatic coding re- gion mutations in the PRL gene were identified. However, four germline vari- ants (c.570G>A, c.205-102T>A, c.312+177T>C and c.269C>T) were detected.

Conclusions:
This study is the first one to confirm that serum PRL level ele- vation among UL patients is not connected to somatic mutations in the PRL gene. However, PRL genetic polymorphisms may indirectly contribute to the disease etiology.