Bilateral trigger thumbs in identical twins.

Bilateral trigger thumbs in 4-year-old identical male twins are reported. To the authors' best knowledge, this is the first true description of this condition in identical twins. All four thumbs were treated by surgical release of the A1 pulley, with good results. The causes proposed for congenital and acquired trigger thumb are discussed, and it is concluded that the cases described here support a genetic predisposition to the condition.