Question: Did they ever explain what happened to Brendan, who was missing this season?
Answer: The actor that also played Brendan quit acting altogether.
Step by Step (1991)
1 question in season 7
Starring: Patrick Duffy, Brandon Call, Suzanne Somers, Staci Keanan
Genres: Comedy
Crazy Love - S6-E1
Factual error: Carol and Frank leave for a romantic weekend and Dana begins to tutor Rich for a test in English Literature. When Frank and Carol return on Sunday Rich has not only studied for the test but also TAKEN the test and gotten the results back. How is that possible over a weekend?
Cody Lambert: Woah! A Canadian penny! Now I can buy bubble gum! That is, if I go to Canadia.
Answer: According to the SBS website, Brendan's disappearance was never really explained. He just kind of faded out. He was hired as the cute "little" one and as he got older he wasn't as cute. When the Lamberts had the little girl, they got their cuteness factor back and didn't need as many kids around.
Carol and Frank continued to tell people they had seven children throughout the remainder of the show's run, but they never referred to Brendan after season 6.