DescriptionThe participants in UKB are currently being genotyped. The results from the first 150,000 are available now, with the results from the remainder expected to become available in 2017.
Genotyping is being done using two closely related arrays, referred to as the UK BiLEVE array and the UK Biobank Axiom array. The BiLEVE array was designed first and run on ~50,000 participants. The UKB Axiom array was designed subsequently with a view to maximizing marker overlap as much as possible between the arrays and will be run on the remaining ~450,000 participants. The UKB Axiom array has over 820,000 SNPs and indel markers, and the UK BiLEVE array is very similar having over 95% common content. After data cleaning there are over 807,000 distinct genetic locations represented.
The two datasets have been merged to produce a single format, with SNPs present only on one particular array being marked as missing-values for participants analysed with the other array.
To determine which array was used for a participant use Field 22000 - batches beginning with E were done on the UK BiLEVE array, and batches beginning with K were done on the UK Biobank array.
Please note that in order to conduct any type of genetic analysis, including genome-wide association studies (GWAS), researchers should include all calls & imputation (category 100315), confidences (category 100316) and intensities (category 100317) data-fields in their basket.