Snapshot A 32-year-old prisoner in the county detention center has been denied parole due to his repeated disregard of civil obediance and overtly aggressive behavior. He is very tall and has severe acne. Upon return, he agrees to participate in a genetic study looking at markers for aggressive behavior in humans. Introduction Genetic abnormality where males are born with two copies of the Y chromosome (47XYY) Most patients appear phenotypically normal login to view 2 more bullets Genotype has been found in increased frequency among males of correctional facilities Hypothesized to impart more aggressive and potentially violent behavior in affected males Presentation Symptoms login to view 1 more bullet Physical exam login to view 5 more bullets STUDIES Genotyping login to view 1 more bullet Differential Differential diagnosis may be limited to other genetic disorders sharing tall height as characteristic, though differ markedly in other aspects, including Klinefelter's syndrome and Marfan syndrome DIAGNOSIS Given normal phenotype in most cases, usually diagnosed incidentally Treatment Prevention login to view 1 more bullet Medical management login to view 2 more bullets Complications Antisocial behavior may result in remediation at correctional facility/imprisonment Prognosis Very good to excellent Most cases live very happy and fulfilled normal lives