The Potential Roles of 77C>T Variant and Growth Hormone-Releasing Hormone Elevation in Pituitary Adenoma Cases Associated with Acromegaly

Abstract

Background: Acromegaly (ACM) is an endocrine disorder characterized by the elevation of growth hormone-releasing hormone (GHRH), growth hormone (GH), and insulin-like growth factor-1 (IGF-1).

Objectives: This study aims to elucidate the correlation between the 77C>T (rs368475481) variant in the GHRH gene and elevated growth hormone-releasing hormone levels in patients with acromegaly.

Materials and Methods: This study, conducted from January to August 2024, analyzed 80 samples from Iraqi acromegaly patients collected at the Diabetic National Center, Al-Mustansiriyah University, alongside 80 samples from healthy individuals. Growth hormone and insulin-like growth factor-1 levels were quantified using chemiluminescence immunoassay, while growth hormone-releasing hormone levels were measured by enzyme-linked immunosorbent assay (ELISA). The 77C>T (rs368475481) variant was detected via Sanger sequencing to assess genetic variation between acromegaly patients and healthy controls.

Results: The serum levels of GHRH, GH, and IGF-1 were elevated in acromegaly patients compared to controls. The genetic results indicate the presence of the rs368475481 variation in the amplified fragment of the GHRH gene (a 791 bp amplicon including exons 2 and 3, and intron 2), with the CC homozygous genotype observed in 80 (100%) of controls and 40 (50%) of acromegaly patients. The CT heterozygous genotype was present in 40 (50%) of acromegaly patients.

Conclusion: The elevated levels of growth hormone-releasing hormone and the GHRH 77C>T variant in the GHRH gene were shown to be associated with pituitary adenomas, which cause acromegaly.