sql server 2008 r2 DBCC checktable error
One suggestion would be to identify the index that is causing the problem.

select o.name as tablename, i.name as indexname 
  from sys.objects o 
  join sys.indexes i 
    on o.object_id = i.object_id 
  where i.index_id = 7 
    and o.object_id = 1253579504


and then drop it. If you believe you're going to need this index then I'd script out the DDL before dropping it, drop it, recreate it, and then rerun your DBCC. Since its index_id is 7 I'm going to assume that this table is potentially over-indexed so YMMV with actually recreating it.

If dropping the index doesn't work, then I would always recommend a last-known-good backup to which you can restore. Also, if this has been occurring for a while, the backup will also have the corrupted index since a full backup is a page-by-page copy of the database (+ some transaction log).