Question

Question Posted 07/09/15:
How is APOE4 coded in the ADNI1 data set? Is it (0,1) or (0, 1, 2). If it is (0, 1) then is the presence of 2 a typo? If it is (0,1,2) then what do they mean?
Thank you.
Response posted 07/09/15 by Danielle:
If you are using the ADNIMERGE dataset, the APOE4 variable represents the number of E4 alleles, so 0, 1, and 2 are all allowable values.