History ChuckCunninghamSyndrome / LiveActionTV

** 4 Tones: John is never seen again after Season 1. Kellylee takes his place. Later, Starr disappears after season 2 and is replaced by Melissa, who previously appeared with John in season 1

** Poetry Square: Helen, Lyneya, and Akela are never seen again after Season 1. Pay, Paige, Clan, and Joshua take their places.

** 4 Tones: John is never seen again after Season 1. Kellylee takes his place. Later: Starr disappears after season 2 and is replaced by Melissa, who previously appeared with John in season 1

** 4 Tones: John is never seen again after Season 1. Kellylee takes his place.

** The most prominent semi-example is Laurie, Eric's older sister. She was a recurring character in season one, and then a regular in season two and three. Her actress then left the show, and Laurie wasn't mentioned at all. (At least not by name, though Red mentioned having "kids".) Laurie came back (played by a different actress) for recurring appearances in season five and six before disappearing again, though she was mentioned in passing several times. When Kitty considers Donna part of the family at the end of the series, they lampshade Laurie's disappearance, wondering where she is.

** Miss King, a sexy female clerk at Mainwaring's bank whom the writers admit was introduced solely for the purpose of being MsFanservice. She disappears after series two and is never heard from again, although she did play a very small role in ''Film/DadsArmy1971''.
** A couple of platoon members also disappeared with no explanation: Private Bracewell, who appears in the first episode only (WordOfGod states he was cut because the writers felt his character was too much like Godfrey's) and Private Desmond, an AscendedExtra who goes on a mission with the main cast in the episode "Sons of the Sea", then is never heard from again.
** Private Cheeseman appeared for one series and then disappeared entirely, with no explanation. Word of God states this was a case of ShooOutTheNewGuy since neither the audience nor the rest of the cast liked him. Cheeseman's storyline was that he was a reporter who temporarily joined the platoon in order to write news stories on them, thus, it can be assumed he left at the end of his assignment; but there is no mention of this in the show, he doesn't get a goodbye and is never referenced again.

* The first season of ''Series/ItsAlwaysSunnyInPhiladelphia'' establishes that Charlie has a sister. She is never referenced again, and flashbacks and dialogue from future seasons imply that Charlie is an only child.

* ''Series/TheBigComfyCouch'' The Foley Family disappears after season 5, as their segments were dropped following "Don't Tell"

** In one early episode, we see Topanga's older sister, Nebula. She is never referred to again and indeed Topanga is later stated to be an only child. However, this is back when Topanga was going through her CloudCuckoolander phase, and this makes her word a bit unreliable. Nebula could be anything from a "soul sister" in the hippie sense or just a friend she calls a sister.
** In earlier seasons, Shawn had at least two siblings before Jack came into the picture. There was an older brother who Cory caught stealing or something on video, and an older sister he called after Cory had him help straighten his hair. However, because these people are rather scummy, it makes sense that they would not appear again. Then comes the matter of [[spoiler: Shawn's mother revealing she did not give birth to him]] and one wonders if they were his brothers in the first place.
** Minkus, a recurring character from the first season, also disappears without a trace. Later, when the show became more meta, they had him return for their high school graduation, pointing off-stage and saying that all his classes had been [[TwoTeacherSchool down the other hallway]]. The kids wave down the hall, shouting hello to their old teacher [[Creator/AnthonyTylerQuinn Mr. Turner]], who had ''also'' been Chucked. (Ironically, [[Creator/LeeNorris the actor playing Minkus]] was one of the three ''[[Series/TheTorkelsons Torkelsons]]'' to survive the ReTool into ''Almost Home''). None of this stopped Minkus's son from getting into ''Series/GirlMeetsWorld'', though.
** Cory's sister, Morgan, almost got the Chuck treatment. She disappears entirely at the end of season 2. Her character is brought back in the middle of season 3 (as a different actress), and remarks, on her first appearance, "That was the longest time out I've ever had!"