MagicCity, I'm not sure that is the case.
Go here: http://www.treasury.gov/resource-center/sanctions/Terrorism-Proliferation-Narcotics/pages/index.aspx
From the website: "Palestinian Legislative Council (PLC) list - (This list is NOT part of the Specially Designated Nationals [SDN] List)"
Just to double check, I just searched the SDN list for a name on the PLC list "AL-QREINAWI, Huda Naim". There were no results.
ETA: I think many vendors combine the two lists as a matter of course, but I would check to make sure that is the case. Even though the PLC list hasn't been updated since 2006, the location of the list on OFAC's website has changed over the years. The mechanism some OFAC solutions use to scan the list(s) involves 'pointing' the software to the web address of the text file of the list. If the web address in the system is no longer valid, the software might not be retrieving the right information.