Genotyping of the TwinsUK dataset (N = ~6,000) was done with a combination of Illumina HumanHap300, HumanHap610Q, 1M-Duo and 1.2MDuo 1M chips. Intensity data for each of the arrays were pooled separately (with 1M-Duo and 1.2MDuo 1M pooled together) and genotypes called with the Illuminus32 calling algorithm, thresholding on a maximum posterior probability of 0.95 as previously described 29.
