Brother: Konstantin Gessen ("Keith Gessen", editor, b. 1975)

Author of books:
Dead Again: The Russian Intelligentsia After Communism (1997, intellectual history)
Ester and Ruzya: How My Grandmothers Survived Hitler's War and Stalin's Peace (2004, biography)
Blood Matters: From Inherited Illness to Designer Babies, How the World & I Found Ourselves in the Future of the Gene (2008, memoir)
Perfect Rigour: A Genius and the Mathematical Breakthrough of the Century (2009, biography)
The Man Without a Face: The Unlikely Rise of Vladimir Putin (2012, biography)
Words Will Break Cement: The Passion of Pussy Riot (2014, music studies)
The Brothers: The Road to an American Tragedy (2015, biography)