Although the genome scanning services offered by companies such as 23andMe, deCODEme, and SeqWright have been front and center in the press the last few weeks, I’m sure that the following information will not be included in any of the reports.
Two different sources have concluded that the scanning service offered by 23andMe and deCODEme, who use different types of Illumina SNP Chips, are highly reproducible. In January 2008, Ann Turner compared the results of testing at deCODEme and 23andMe, and concluded that of the 560,163 SNPs that overlapped and had a “call” (meaning there was a measurable result), they agreed on 560,128 and disagreed on 35. Ann wrote in January:
In all of [the disagreed calls], one company would make a homozygous call while the other company made a heterozygous call – there were no cases where they made a completely discordant call. All in all, I’d say that is pretty impressive.