Instead of iframe, it is recommended to use custom HTML header, footer, left and right panel content to frame the form.
Custom HTML content can be loaded in IGAM by taking the following steps:
1) In the IGAM module, Tools menu > Preferences
2) Click Options under Applicant/Grantee View
3) Click Edit to make changes
4) Click the Graphics tab, then the HTML button at bottom left
5) Here, you may browse to your Header/Footer/Other HTML files that you wish to upload in order to frame your GrantRequest.com site
Please be advised that use of iframe will not be supported by MicroEdge and that following the above steps is the best means to resolve the issue.