We report on a patient with primordial growth retardation, mental retardation, and minor anomalies (triangular face, open sagittal suture, frontal bossing, telecanthus, upturned nose, micrognathia, and small mouth with downturned corners). The diagnosis of Russell-Silver syndrome (RSS) had been considered but was abandoned when cytogenetic evaluation showed a partial trisomy 1q or duplication 1q (46,XY,15, + der(15)t(1;15)(q42;qter). Data from another 5 reports of dup(1)(q42-->qter) do not allow delineation of a typical syndrome. However, individuals with dup(1q), del(15q), and Russell-Silver syndrome share common manifestations (i.e., low birth weight, growth retardation, triangular face, low set/abnormal ears, micrognathia, renal anomalies.