Differentiate sequenced and imputed variants in BGEN files

Question

[user230613]

Hi there!

I have recently started working with UK Biobank data, particularly with the imputed BGEN files (for whoever has access to UK Biobank, the files are located at Bulk/Imputation/UKB imputation from genotype). I am also very new to the field of imputation, so I am sorry in advance if the question is naive. Is there anyway to differentiate those variants in the BGEN files that have been sequenced from those that have been imputed?

Thank you in advance