There are two possible remedies. One is for you to print, sign and mail your own tax return since you cannot e-file. It will be months before the IRS processes your son's amended return and it will not "catch up" in the system this year.
Or... use an IP PIN to e-file:
GET IP pin in order to e-file if your dependent’s SSN was claimed on another return
https://www.irs.gov/newsroom/irs-takes-steps-to-help-prevent-refund-delays-by-accepting-duplicate-de...
https://www.irs.gov/identity-theft-fraud-scams/get-an-identity-protection-pin
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**