Dragonborn Racial Move(s) in Dungeon World?

So after settling on and falling in love with Dungeon World's ruleset and playstyle, I figured it'd be a good way to get my nephews (10 and 11) into tabletop stuff. This after having stalled out with 4e D&D due to its propensity to lag in combination with the tactics-heavy minis-board-game style combat which my boys just don't have the attention span for.

Got them into playing Wrath of Ashadralon though, a fun 4e "light" dungeon explore game, which they've learned easily enough.

Thing is, after always playing the Dragonborn Wizard character in WoA, he wants to play one in our DW campaign as well.

Seeing as how he wants to be a Wizard who is a Dragonborn rather than the other way around, at least I don't have to write up a whole new playbook for Dragonborn and can just add a racial feature to the Wizard class.

TL;DR: Thoughts/comments/suggestions on Dragonborn Wizard racial feature in Dungeon World?

My idea:

Magic and its workings are ingrained into the history of the descendants of the mightiest of magical creatures. Take +1 whenever you Spout Lore about Magic or Magical History.

To me it's obvious that a dragonborn racial move would have to incorporate the breath weapon somehow. At least when playing with 11-year-olds. So:

Dragonborn breath
You breathe forth a plume of fire, ice, acid mist or lightning (choose one at character creation, then always use that one). Anyone within its reach takes 2d4 damage.

is a cantrip for you.

I'm a bit unsure about the balance. This is essentially a close-range magic missile as a cantrip, as compared to the Elf racial which gives an ordinary Detect Magic as a cantrip. An alternative is to make it 2d6 damage, i.e. a close-range fireball, and have it count as a level 1 move that you have for free (but need to prepare). That's a bit weird though, because it's not really a spell. If it's a cantrip you get away with it because the spellcasting move fits: on a 7-9 you put yourself in a spot, mess up your future spellcasting (including firebreathing) or lose the ability temporarily (run out of fire oil in your belly). They kinda work for the breath weapon.