Huh. I am sure there is one study you are missing. I remember another gwas right after the first.
I recall 4 gwass including latest.
You must be thinking about this: http://www.pnas.org/content/111/38/13790.abstract
I will include it too, then, although I am not sure about the validity of the proxy-phenotype method.
How many of the 7 alleles have other ones in LD?
At some point, maybe you should try weighting the factor analysis as some "hits" will be more reliable than others.
(Could you make a table for us? -- listing x independent alleles along with the ones in LD.)
I will add it to the paper I am working on. Gonna post it here soon.