AceShowbiz -

Despite not having an official pilot order, CBS is moving forward with its project of "The Big Bang Theory" prequel which centers on young Sheldon Cooper. After an extensive process of casting, the spin-off has reportedly cast young Sheldon and his mother.

Iain Armitage ("Big Little Lies") has been tapped to play young version of Sheldon Cooper, who is portrayed by Emmy winner Jim Parsons on "The Big Bang Theory". Meanwhile, Zoe Perry ("Scandal") is set to star on the prequel series as Mary Cooper, Sheldon's mother. It's such a smart casting, for Perry is a daughter to Laurie Metcalf, who plays Sheldon's mother on "The Big Bang Theory".

Sheldon's childhood has been referred several times on the sitcom. He grows up as a very gifted yet peculiar child of a deeply religious mother and a redneck father in East Texas. Often being the bullies' target, Sheldon enters college at the age of 11 and gets his first PhD at 16.

Armitage's TV gigs include HBO's "Big Little Lies" adaption, where he plays Shailene Woodley's on-screen child, and "Law & Order: Special Victims Unit". He will be seen in three upcoming movies which will be released this year, namely "I'm Not Here", "Our Souls at Night" and "The Glass Castle".

Meanwhile, Perry plays a recurring role in season 6 of "Scandal" opposite her father, Jeff Perry. Her other TV credit is ABC's thriller series "The Family" as Jane.

The potential prequel series, which is titled "Sheldon", will be written by "The Big Bang Theory" co-creator Chuck Lorre alongside showrunner Steve Molaro. Fellow co-creator Bill Prady is said to help working on the script. "Sheldon" will follow young Sheldon and reportedly none of "The Big Bang Theory" stars will be cast on the spin-off. However, Parsons will serve as the executive producer alongside Molaro, Prady and Lorre.

Both CBS and producers Warner Bros. TV reportedly decline to comment on the casting report.