The adipocyte-derived protein adiponectin is highly heritable and inversely associated with risk of type 2 diabetes mellitus (T2D) and coronary heart disease (CHD). We meta-analyzed 3 genome-wide association studies for circulating adiponectin levels (n = 8,531) and sought validation of the lead single nucleotide polymorphisms (SNPs) in 5 additional cohorts (n = 6,202). Five SNPs were genome-wide significant in their relationship with adiponectin (P≤5×10-8). We then tested whether these 5 SNPs were associated with risk of T2D and CHD using a Bonferroni-corrected threshold of P≤0.011 to declare statistical significance for these disease associations. SNPs at the adiponectin-encoding ADIPOQ locus demonstrated the strongest associations with adiponectin levels (P-combined = 9.2×10-19for lead SNP, rs266717, n = 14,733). A novel variant in the ARL15 (ADP-ribosylation factor-like 15) gene was associated with lower circulating levels of adiponectin (rs4311394-G, P-combined = 2.9×10-8, n = 14,733). This same risk allele at ARL15 was also associated with a higher risk of CHD (odds ratio [OR] = 1.12, P = 8.5×10-6, n = 22,421) more nominally, an increased risk of T2D (OR = 1.11, P = 3.2×10-3, n = 10,128), and several metabolic traits. Expression studies in humans indicated that ARL15 is well-expressed in skeletal muscle. These findings identify a novel protein, ARL15, which influences circulating adiponectin levels and may impact upon CHD risk.,
P L o S Genetics (Print)
This work was funded by the European Commission 7th Framework Programme; grant id fp7/201865 - GENETIC FACTORS FOR OSTEOPOROSIS (GEFOS), This work was funded by the European Commission 7th Framework Programme; grant id fp7/201413 - European Network for Genetic and Genomic Epidemiology (ENGAGE)
Erasmus MC: University Medical Center Rotterdam

Richards, J.B, Waterworth, D, O'Rahilly, S, Hivert, M.-F, Loos, R.J.F, Perry, J.R.B, … Spector, T.D. (2009). A genome-wide association study reveals variants in ARL15 that influence adiponectin levels. P L o S Genetics (Print), 5(12). doi:10.1371/journal.pgen.1000768