I've always wondered, is there any Quartermaine-Cassadine family connection or history? Because they are two of GHs core families, where if you were to look at Spencer's-Quartermaines, the Spencer-Cassadine clan, and the Quartermaine-Corinthos, the connections/relationships and history is prominent.
Actually, yes. One of Mikkos Cassadine’s brothers, Tony, was romantically involved with/engaged to Alexandria “Alex” Quartermaine, Edward’s niece. Both died in 1981 when they walked in the ice chamber of Mikkos’ weather machine. Nikolas Cassadine was married to Emily Bowen-Quartermaine, Alan’s adopted daughter. Both of Mikkos Cassadine’s illegitimate daughters Alexis Davis (born Natasha Alexandra Mikkosovna Cassadine, raised as Alexis Davidovitch) and Kristina Cassadine were both involved with Ned Quartermaine (formerly Ashton). Alexis actually left Ned at the altar. Even though Alexis’ middle daughter Kristina is a Corinthos, Ned originally said he was the father in order to protect the child from Sonny and mob violence, which killed the original Kristina. For about the first year of life, Kristina Davis was raised as a Q in the mansion. Alexis had lost custody after killing Luis Alcazar and faking DID, so she posed as the Q butler. Sam McCall, a Cassadine via mom Alexis, married two Quartermaine heirs: twins Jason Morgan and Andrew “Drew” Cain. She had children by both, Danny (Jason) and Emily Scout (Drew). Stefan Cassadine fell in love with Chloe Morgan, a Quartermaine cousin (actually a distant to Q matriarch Lila) and one of Ned’s wives, who was murdered by his brother Stavros. As for non-romantic Quartermaine/Cassadine connections, I think Helena Cassadine coerced Tracy Quartermaine into working with her at one point.