Dedupe rules for profiles in civicrm
There is no inbuilt way for doing this directly for Profiles with CiviCRM.

Event management is the only feature in CiviCRM that I know can do this since you can specify the Profile and the matching rule - not suggesting you have folk sign up to an event purely to achieve this but hey, you could ;-)

For Drupal users, you can build a webform_civicrm form and specify the fields and matching rules to apply and hence get very close to what you are asking for.