Something very comforting about the v high reliability and reproducibility of modern GWAS. I believe the first report of an association between SLC2A9 and uric acid and gout is this paper from a dozen years ago:
https://www.nature.com/articles/ng.106  https://twitter.com/SbotGwa/status/1246783774018473990

I guess that's the first to associate SLC2A9 with gout. @gwascatalog lists this as the first publication to link SLC2A9 to uric acid: http://www.ncbi.nlm.nih.gov/pubmed/17997608 
The GLUT9 gene is associated with serum uric acid levels in Sardinia and Chianti cohorts.
https://www.ebi.ac.uk/gwas/genes/SLC2A9

In total, @GWASCatalog lists 79 studies with genome-wide significant hits for SLC2A9 and uric acid!
The strongest p-value reported in the gwas catalog is 1e-700, but this is incorrect. Yes, I get to mention my favorite pet peeve around underflow. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3663712/

Here's the table from the original paper. I calculate a p-value of about 8e-843. It would be nice to clean this up.

And even that is not the strongest p-value ever published for SLC2A9. That honor goes to Nasa Sinnott-Armstrong and team for the 38 biomarkers paper currently in biorxiv https://twitter.com/Eric_Fauman/status/1184814396087783427

SLC2A9 for uric acid is the lime green dot at the start of chromosome 4 with a -log10(p) of about 3500 (p=1e-3500)