Retn, which encodes resistin, is a gene of significant biological importance. Resistin is an adipocytokine secreted by adipocytes that plays a crucial role in glucose and lipid metabolism [10]. It may be involved in various physiological and pathological processes, and genetic polymorphisms of Retn can potentially influence these functions, making genetic models valuable for its study.

Numerous studies have explored the associations between Retn genetic polymorphisms and different diseases. In alcohol-dependent patients during acute alcohol withdrawal, the A allele of Retn rs1477341 was associated with susceptibility to depression symptoms [1]. The +299(G>A) SNP in Retn was associated with type-two diabetes mellitus (T2DM), and the CA haplotype of -420 and +299 SNPs was related to T2DM risk [2]. In the Chinese Han population, certain Retn polymorphisms were associated with the susceptibility of alcohol-induced osteonecrosis of femoral head [3], and SNP rs3745368 was related to the clinical stage of the disease. For hand osteoarthritis (HOA), SNP rs3745368 from Retn was associated with an increased risk of HOA and with Kellgren-Lawrence grade in HOA patients [4]. In breast cancer, the AG genotype and at least one A allele of Retn SNP rs3219175 were associated with a higher chance of developing breast cancer, and the CT genotype of rs7408174 was linked to late-stage disease [5]. A meta-analysis of 23 studies found that the Retn-420C/G polymorphism might be linked to T2DM susceptibility in a way influenced by patient age [6]. In the Chinese population, the Retn-420G allele increased the risk of acne vulgaris [7]. In the Chinese Han population, certain Retn polymorphisms were associated with a reduced risk of steroid-induced osteonecrosis of the femoral head, and rs3745367 was related to the clinical stage, while rs1477341 was correlated with lipid levels [8]. In Labrador Retrievers, the RETN variant allele frequency was not significantly different among control, copper-associated hepatopathy (CAH), and intermediate populations [9]. In goats, Retn inhibits the differentiation of intramuscular preadipocytes, probably through regulating the expression of related genes [10].

In conclusion, Retn plays a role in multiple biological processes such as metabolism and cell differentiation. The study of Retn genetic polymorphisms through various research models has revealed its associations with a wide range of diseases including depression, T2DM, osteonecrosis, HOA, breast cancer, acne, and potentially CAH in dogs. These findings contribute to a better understanding of the disease mechanisms related to Retn and may provide insights for disease prevention and treatment.