You close those other bugs as "same-source-fix". As a developer, when you root-cause the bug, you'd inform QA that the bug you root-caused will have an impact

You close those other bugs as "same-source-fix". As a developer, when you root-cause the bug, you'd inform QA that the bug you root-caused will have an impact on X, Y, and Z, and that they will need to rerun those tests after your same-source-fix is deployed. They will then verify that the 1 change propagated and resolved the other bugs. This comes down to open and active communication between developers and QA. If you can't approach your QA team and tell them that they may see X Y or Z because of bug 654654, you need to rethink your development, QA, and overall-business processes. Likewise, your QA should be actively communicating to you and say, "we're seeing X and Y" to which you can reply, "yes, that is to be expected. Also, I think Z may occur. No worries, we've identified the issues and you'll get an update for all 3 soon"