title: Absence of the XYY syndrome amongst 164 police force students in Mexico City.
mesh_terms: D000293:Adolescent; D000328:Adult; D000374:Aggression; D004651:Employment; D006801:Humans; D008297:Male; D008800:Mexico; D012729:Sex Chromosome Aberrations / Q000453:epidemiology*; D014997:XYY Karyotype / Q000453:epidemiology*