Lack of Evolution, Abundance of Abnormalities

Everyone knows that the way to check if someone is Quirkless is to see if they have two joints in their pinky toe. It's the sign that the person has no Quirk- that they haven't reached the next stage in evolution that most people have.
However, most people don't realize that there are *other* differences between the Quirked and the Quirkless, other parts that haven't evolved.
Or: 5 times 1-A thinks Midoriya is dying and/or sick, and the 1 time the truth is (partially) spilled.