Jean Kasem was one of five children, with siblings Jeanette, Shirley, Joan and Tommy Thompson, of Irene Celia Thompson (1919-2008) and Herbert Owens Thompson Sr. (deceased). She lived in Portsmouth, New Hampshire, before her civil-servant father moved the family to Guam in 1963 to help stop her recurring pneumonia. She attended the University of Guam at age 16, but after marrying a U.S. Navy lieutenant when she was 17, she left to work as a waitress and saleswoman on U.S. military bases throughout the Pacific Ocean to which her husband was posted. The marriage lasted six years. Kasem then moved to California and unsuccessfully attempted to find work in broadcast journalism. Frustrated, she joined an acting workshop and soon found roles on such TV series as Matt Houston, Fantasy Island and Alice.
Kasem played the recurring role of Loretta Tortelli, the dimwitted wife of Nick Tortelli (Dan Hedaya) on Cheers and as a cast-member of the short-lived spinoff The Tortellis. She also had a brief appearance in Ghostbusters as one of Louis Tulley's party guests. Kasem has also worked as voice actor for such animated television series as Darkwing Duck, 2 Stupid Dogs, Shaggy & Scooby-Doo Get a Clue!, Johnny Bravo, and Mother Goose and Grimm.
In 1989, Casey Kasem purchased a house built in 1954 and located at 138 North Mapleton Drive, previously owned by developer Abraham M. Lurie, as a birthday present for her. In 2013, he listed it for US$43 million.
In October 2013, Kerri Kasem, one of Casey Kasem's three children from his first marriage, said her father was suffering from Parkinson's disease. On October 1, Kerri Kasem, her siblings and Casey Kasem's brother protested outside Casey and Jean Kasem's home, saying Jean Kasem had been preventing contact with Casey Kasem for three months. On October 7, Julie Kasem and her husband, Dr. Jamil Aboulhosn, filed a conservatorship petition to place Casey Kasem under their care.
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- Norbom, Mary Ann (March 16, 1987). "Playing Dumb, Jean Kasem Gives a Brassy Tint to The Tortellis". People 27 (11). Retrieved October 1, 2013.
- "Kasem, Jean, Patents". United States Patent and Trademark Office. Retrieved October 1, 2013.
- Fitzpatrick, Laura (July 07, 2009). "Radio Host Casey Kasem". Time. Retrieved October 1, 2013. "Married his current wife, Jean ... in 1980. ... In 1990, after suffering eight miscarriages, the couple had a daughter, Liberty Jean Kasem."
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- Willett, Megan (April 08, 2013). "House of the Day: Casey Kasem Is Selling His Crazy LA Mansion For $42 Million". BusinessInsider.com.
- Pennacchio, George (October 01, 2013). "Casey Kasem's family feud: Wife won't let kids, friends see him?". Los Angeles, California: KABC-TV. Retrieved October 2, 2013.
- "Casey Kasem Family Feud: Cops Called". TMZ.com. October 1, 2013. Retrieved October 2, 2013.
- Duke, Alan (October 8, 2013). "Casey Kasem's kids take stepmom to court". CNN. Retrieved October 16, 2013.