FVA Not for points English to Italian Bus/Financial Finance (general) mortgages

I am making a glossary, and wondering how I can translate "subprime mortgage" into Italian.

Example sentence:
"Due to our low credit rating, we can only qualify for a subprime mortgage".
Source: http://www.businessenglishpod.com/2009/04/22/vv-13-financial... (it is a term used in the video)

Thanks in advance! :)