Bilateral trigger thumbs in 4-year-old identical male twins are reported. T
o the authors' best knowledge, this is the first true description of this c
ondition in identical twins. All four thumbs were treated by surgical relea
se of the A1 pulley, with good results. The causes proposed for congenital
and acquired trigger thumb are discussed, and it is concluded that the case
s described here support a genetic predisposition to the condition.