The Fall of the House of Usher

The incest in "The Fall of the House of Usher" by Edgar Allen Poe reminded me of the TV show Game of Thrones, a part of a series of books called A Song of Ice and Fire. In the show, there is a family called the Targaryen that have ruled the seven kingdoms of Westeros for 300 years. They wed brother and sister and had children that did the same, just like the Ushers. The Targaryens also fell because of the last king that was nicknamed the "Mad King". I think that after all the years of incest, the offspring got weaker and weaker because of consequences of incest. The next king that conquered the seven kingdoms married a lady that had a twin brother. They also committed incest but it is extremely forbidden from them because they don't come from the same place as the Targaryens and have gods that forbid incest. They made the crime even worse by passing off their children born of incest as the king's own children. This led to many complications throughout the show, ultimately starting a war of 5 kings. It seems to me that any kind of incest is very bad and will always have dire consequences.