Can you be born with an Open Bite?

When my autistic son was 3 he had major dental work done. At that time the orthdontist said he had a severe underbite that would need to be corrected later. Well its been 8 years and the regular dentist just told me he had a severe open bite. My question is can you be born with this problem . I know I've read that pacifiers, bottles , thumb sucking could do it, but he's never had those habits.