'' The Lion 's Mouth Opens '' is a 2014 short documentary film . It follows actress and filmmaker Marianna Palka as she pursues testing to learn whether she inherited the genetic mutation that causes Huntington 's disease , an incurable neurodegenerative disease . Directed by documentarian Lucy Walker , the film premiered in a 14-minute version at the 2014 Sundance Film Festival . Later recut into 28-minute version , it was broadcast on HBO on 1 June 2015
2014 Sundance Film Festival
2014 Sundance Film Festival
The Lion's Mouth Opens