Molecular studies on preproghrelin gene: Signal peptide, ghrelin coding region and variants – A brief report focusing on rs34911341 polymorphism

Background: Ghrelin is a hormone that exhibits effects in a lot of biologic processes, such as food intake regulation, gastrointestinal motility and carbohydrate metabolism. Ghrelin is encoded by human preproghrelin gene (GHRL), reported with four exons. However, experiments suggested a new molecular structure for this gene. Objective: This study aims to clarify by a simple representation GHRL and its products, showing the variants described for this gene up to this moment. Methods: The GHRL sequence for molecular comparisons was obtained from GeneBank. The dbSNP was used to search variants and the PubMed, Scielo and Science Direct databases to investigate related studies. Results: The new molecular structure of GHRL includes a new exon 0 and an extended exon 1, located in the originally identified region of intron 1. Examples of GHRL products are signal, ghrelin and obestatin peptides and these molecules exhibit different effects on the organism. Thus, polymorphisms in these gene regions have been associated with a vast number of clinical effects, including metabolic disorders. We identified 11 genetic variations in the region of the GHRL which encodes for the signal peptide and 23 polymorphisms in the ghrelin coding region. One of them, rs34911341, has been associated with some disorders such as diabetes, hypertension and obesity. Conclusion: In this scientific article we turned GHRL a little bit more informative for readers. Furthermore we highlighted the current reported GHRL genetic variations associated to signal and ghrelin peptides, but only the variant rs34911341 has been associated with metabolic disorders.