Bofinger et al. [Am J Med Genet 38:1-8, 1991] reported on a four-generation family with an unusual segregation pattern involving a translocation t(10;16)(q26.3;p13.1). All relatives either had a balanced or unbalanced translocation. We report on five additional relatives, none of whom have a normal karyotype. This unusual segregation pattern may be due to chance or be the result of meiotic drive.