I've been presented with an interesting situation for a client and I'm wondering if this is something I can work out for them. 

My client needs a Sch C filed for their income and they live at home with their parents, whose name is on the deed to the house, however, they are the ones paying for the mortgage on the home. Since it's not in their name, they can't claim the Mortgage Interest on their return. However, what I'm looking to learn here is if they claim the Home Office deductions for their space and what they use, can they claim the equal portion of their Home Office from the Mortgage Payments/Interest?