Lex is just a nickname for Alexander Luthor in Smallville.
My name is lex!
Lex Medlin's birth name is Lex Michael Medlin.
Lex Lovett's birth name is Wayne Meyer.
Yvonne Lex's birth name is Douliez, Yvonne.
Lex Henderson's birth name is Ibrahim Badmus.
Lex Schoorel's birth name is Alexander Frederik Schoorel.
Lex Shrapnel's birth name is Alexander Carey Shrapnel.
Lex Verkerk's birth name is Jacques Lodewijk Alexander.
Lex Kreps's birth name is Alexis John Kreps.
Yara Lex's birth name is Iracema Pedrina Barreto.
Lex Marinos's birth name is Alexander Francis Marinos.
Lex Lamprey's birth name is Alexander Jon Lamprey.