How can I enforce validation for generic properties on members that are marked as mandatory?

In my registration form, if I try to submit a blank form, I get an error for email and username, but not the other fields I have marked as mandatory. If I fill out email and username, but not the other fields, Umbraco displays an error and the member is created without the mandatory generic properties.

Is there a way I can add server side validation when creating or updating members through a registration or edit profile form?

Thanks!