alter the 26 (A-Z) parent links so that just the menu link text is displayed without its associated hyperlink
special menu items:

Special menu items is a Drupal module that provides placeholder and separator menu items.

A placeholder is a menu item which is not a link. It is useful with dynamic drop down menus where we want to have a parent menu item which is not linking to a page but just acting as a parent grouping some menu items below it.

https://drupal.org/project/special_menu_items