Basically what is says. Quirks and Perks that make sense as minor glitches or benefits of genetic engineering.
I'll start.
Juvenal Hair Pattern This can work either as a Quirk or a Perk, depending on the reactions the PC gets. Basically the PC went through Puberty but they didn't gain adult body hair. Generally they seem to have no body hair period and this includes underarm and pubic hair. Males have no beards, but they don't go bald either.
Late Onset Puberty Basically puberty is much closer to full brain maturity. The would be social issues for PCs with the Youth disadvantage who haven't gone through puberty yet.
Puberphonia This is the real world problem of puberty not altering the vocal range. Explained
here!
Please give us your items.