Generally it's up to the lender to properly evaluate the person taking out the loan to work out the risk. Generally, the riskier a loan is, the higher the interest rate. This works the same way with the consumer- your credit score is a reflection of how "risky" you are to make a loan to. Bad credit score, high interest rates.
Yeah, and it's exactly these checks that the Bush administration undermined leading up to the property market crash.
See "American Dream Downpayment Act" as one of the programs they enacted. This aloted a stack of money to pay the down payments and closing costs of low-income families to get a home loan, and made a special point of how it would help "minorities". In my opinion the real reason for this was political - if you hook black people in with 30-year mortgages, they're going to be subsceptible to economic fear at the voting booth - i.e. you can get them to vote for Republicans.
I've seen a documentary about it, and what happened was that managers were pressuring the people doing the lending paperwork to "sell sell sell" the low-income / minority home loans, because they didn't want to miss out on their share of the government incentives. Plus all the stuff that was enabled by repealing Glass–Steagall.