Genome-wide association study of prolactin levels in blood plasma and cerebrospinal fluid

Background: Prolactin is a polypeptide hormone secreted by the anterior pituitary gland that plays an essential role in lactation, tissue growth, and suppressing apoptosis to increase cell survival. Prolactin serves as a key player in many life-critical processes, including immune system and reproduction. Prolactin is also found in multiple fluids throughout the body, including plasma and cerebrospinal fluid (CSF). Methods: In this study, we measured prolactin levels in both plasma and CSF, and performed a genome-wide association study. We then performed meta-analyses using METAL with a significance threshold of p < 5 × 10^-8 and removed SNPs where the direction of the effect was different between the two datasets. Results: We identified 12 SNPs associated with increased prolactin levels in both biological fluids. Conclusions: Our efforts will help researchers understand how prolactin is regulated in both CSF and plasma, which could be beneficial in research for the immune system and reproduction.