(Ross Lazarus, unpublished). We matched cases and control datasets based on their ethnicity. After correction for ancestry, 110 European American controls and 68 African American controls were excluded on the basis of excessive ancestry which was neither European nor African. This left 1531 European American controls and 1759 African American controls for our study. Cases were tested for cryptic relatedness looking for long segments identical by descent, showing that all cases were unrelated.
