You are still receiving your original refund amount. 

The tax calculator on Turbo Tax resets to zero when you start the amend process.

The amount on your 1040-X is usually either additional refund (Line 22) or an amount due that has to be paid back to the IRS (Line 20). 

However, since you stated that your income was too high to benefit from claiming your son, there would not be a change to your taxes.  If you are removing information that had zero effect on your tax return, then removing it would also have zero effect.