We report on a 41-year-old male with dysmorphic features, marked obesity, profound mental retardation, and aggressive behavior who was recently diagnosed with tetrasomy of the short arm of chromosome 18, [47, XY, i(18)(p10)]. His initial diagnosis, based upon chromosomal analysis at 6 years of age in 1969, was "trisomy F syndrome." Approximately 60 cases of tetrasomy 18p are reported in the literature, with little information regarding their long-term behavioral profiles or outcomes from therapy. We describe the behavioral management as well as the medical and genetic evaluation for this older patient with tetrasomy. With improved preventive care and intervention, patients with rare chromosomal abnormalities are living longer and, therefore, provide insight into the natural history of their disorders. Efforts need to be directed toward behavior management, social skills training, and augmentation of communication if the quality of life of these individuals is to continue to improve.
2006 Wiley-Liss, Inc.