We are all made to believe that Deku is quirkless by this doctor. Then later in the manga we finally get a little hint about this doctor, there's 1 doctor that are very similar, named Daruma Ujiko who is working for All for One. https://bokunoheroacademia.fandom.com/wiki/Daruma_Ujiko
Is it possible that this Doctor stole Deku's quirk when he diagnosed our boy (related to All for One abbility)? My further question is, is it possible that actually all people in BNHA are born with quirk, but got stolen at young age by certain people and made to believe that they are quirkless?