Which of the following systemic diseases does/do NOT predispose a patient to periodontitis?
1. Cyclic neutropenia.
2. Diabetes mellitus.
3. Acquired immunodeficiency syndrome.
4. Hereditary hypohydrotic ectodermal dysplasia.

(4) only

(1) (2) (3)

(1) and (3)

(2) and (4)

All of the above.