That ’70s Show Mocked Its Own Use of Chuck Cunningham Syndrome on Donna’s Sister, Tina That ’70s Show Mocked Its Own Use of Chuck Cunningham Syndrome on Donna’s Sister, Tina In a spotlight on pop culture retcons that 'overturn' past stories, see how That '70s Show made fun of its own use of Chuck Cunningham Syndrome to write out Donna's younger sister, Tina. Read More