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

Author of books:
Dead Again: The Russian Intelligentsia After Communism (1997, nonfiction)
Ester and Ruzya: How My Grandmothers Survived Hitler's War and Stalin's Peace (2005, biography)
Blood Matters: From Inherited Illness to Designer Babies: How the World and I Found Ourselves in the Future of the Gene (2005, nonfiction)
Perfect Rigour: A Genius and the Mathematical Breakthrough of the Century (2011, biography)
The Man Without a Face: The Unlikely Rise of Vladimir Putin (2012, biography)