You’re correct; we asked for Y chromosomes rather than X chromosomes because it’s way easier to have an extra X and not know it than to have a Y and not know it. So if we ask about Y, we can rough-sort into “probably XY” and “probably XX” groups and then look at the statistics for chromosomal deviations within those groups.
You’re correct; we asked for Y chromosomes rather than X chromosomes because it’s way easier to have an extra X and not know it than to have a Y and not know it. So if we ask about Y, we can rough-sort into “probably XY” and “probably XX” groups and then look at the statistics for chromosomal deviations within those groups.