Is it possible for shadowhunters to turn into vampires?

(A little bit of spoilers?)

Just thinking about the Malec situation, Ты know... with the 'Magnus-is-immortal-and-Alec-is-not'.

There's a couple of points I've thought about:

For:
- It's possible with Волколаки (Luke is one)
- In Clockwork Angel, Will has to drink holy water to avoid turning into a darkling

Against:
- Camille says that there's no way for him to become immortal
- It will probably be completely looked down on if he did, anyway.