CBS and Warner Bros. TV are yet to acknowledge the existence of the untitled Sheldon project, but The Big Bang Theory spinoff prequel has been quietly chugging along, casting the two key roles.

Word is that Iain Armitage, currently on HBO’s Big Little Lies, has been cast as Sheldon Cooper, an younger version of the character played by Jim Parsons on the mothership series. And the producers are keeping things as authentic as they can in the genes department by casting Sheldon’s mother, Mary Cooper, with Zoe Perry (ABC’s The Family) whose mother, comedy veteran Lauri Metcalf, plays the part on Big Bang. CBS and WBTV declined comment.

Negotiations between CBS and WBTV for the Sheldon project have been going on for more than four months. They are yet to formally close — thus the parties’ unwillingness to confirm the project — as the network and the studio also are finalizing a two-season pickup for Big Bang.

mary_and_sheldon_1

Details of the Sheldon project are still sketchy but it is described as a Malcolm in the Middle-esque single-camera family comedy centered on the child prodigy Sheldon (Armitage) character at age 10. He lives in Texas with his older brother George, fraternal twin sister (Missy), their mother Mary Cooper (Perry), an overtly devout Evangelical Christian; and father George Cooper, an alcoholic who was never around.

The project comes Big Bang co-creator/executive producer Chuck Lorre, executive producer/showrunner Steve Molaro and Parsons who had the idea and took it to the Big Bang producers. Big Bang co-creator/exec producer Bill Prady also is expected to be involved in some capacity.

As for Big Bang, CBS and WBTV are close to new deals with Melissa Rauch and Mayim Bialik — who had been seeking parity with their co-stars and are expected to get big raises — after inking new pacts with original cast members Parsons, Johnny Galecki, Kaley Cuoco, Simon Helberg and Kunal Nayyar.

Armitage is repped by Abrams Artists Agency and Ryan LeVine at Jackoway Tyerman. Perry is with SDB Partners and Levity Entertainment.