We report on a patient with duplication of 7p15-->pter and review the literature. Patients with partial duplication of the distal 7p, including only the distal segment 7p15-->pter, have a syndrome comparable to that of patients with a larger or complete duplication of 7p. This suggests that the critical region for the dup(7p) phenotype is restricted to 7p15-->pter. The complete clinical phenotype of dup(7)(p15-->pter) includes mental retardation, skull anomalies, large anterior fontanel, cardiovascular defects, joint dislocation and contraction, and gastrointestinal and genital defects. Recognition of the clinical spectrum in patients with a smaller duplication of 7p, and the assignment of this critical region, should prove valuable for accurate counseling, prediction of outcome, and further gene mapping.