GWAS of serum albumin and total protein (provisional)

Albumin, the major plasma protein, transports endogenous and exogenous compounds such as nutrients, hormones, metabolic catabolites, and drugs and maintains intravascular volume by generating oncotic pressure. Diverse conditions, including cancer, liver diseases, and acute and chronic inflammatory states, manifest reduced plasma albumin concentrations. In our previous study (Franceschini e.a. 2012, AJHG) and through transethnic meta-analysis of European-ancestry and Japanese genome-wide association studies, we identified six loci at genome-wide significance (p < 5 × 10−8) for serum albumin,  and three loci for total protein, in up to 25,539 European-ancestry and 10,168 Japanese individuals). Although we observed little evidence of heterogeneity in allelic effects, we found a large number of suggestive GWAS hits for these two phenotypes. This suggests a possibility of type 2 error, i.e. low power, and in the present study we plan to tackle this by increasing the number of participating subjects substantially. We expect to reach 1,000,000 subjects