U.S. house prices rose modestly in the first quarter of 2012, the Federal Housing Finance Agency said Wednesday. The FHFA\'s \'s seasonally adjusted purchase-only house price index was up 0.6 percent since the fourth quarter of 2011. The HPI is calculated using home sales price information from Fannie Mae and Freddie Mac mortgages. Seasonally adjusted house prices rose 0.5 percent from the first quarter of 2011 to the first quarter of 2012. FHFA\'s seasonally adjusted monthly index for March was up 1.8 percent from February. \"Increased affordability and a somewhat smaller inventory of homes for sale are positively impacting house prices,\" FHFA Principal Economist Andrew Leventis said in a release. FHFA\'s expanded-data house price index, a metric introduced in August 2011 that adds transactions information from county recorder offices and the Federal Housing Administration to the HPI data sample, rose 0.2 percent over the latest quarter. Over the latest four quarters, the index is down 1.3 percent. While the national, purchase-only house price index rose 0.5 percent from the first quarter of 2011 to the first quarter of 2012, prices of other goods and services rose 3.2 percent over the same period. Accordingly, the inflation-adjusted price of homes fell approximately 2.6 percent over the latest year, the report said. Annual price increases were highest in Hawaii, with a 10.3 percent increase, and in Washington, D.C., which saw prices rise 9.8 percent. Iowa, Florida and North Dakota also reported strong increases. The weakest prices were in New England, where prices fell 0.7 percent.