The Further Adventures of Lot?

Says in the Bible, which I'm told is the Word of God, that the two daughters of Lot were impregnated by their daddy. Would their kids have been Lot's children or his grandchildren? And were their surnames Lot? It is said nowadays that such close family is apt to make a baby in some way disabled. Were these kids disabled? Retarded, perhaps, by the Devil do you think? Is it possible, or even likely, that Trent Lott is a descendent?