This comment relates to studies implying that, when compared to normally chromosomed individuals, men with XYY are 10 times more likely than XY men to be found in criminal populations. XXY men and XXX women were four to five times more likely to be found in groups of mentally retarded or psychotic patients. However, the initial studies on sex chromosomes were done in mental hospitals and prisons and more recent studies imply that children with sex chromosome abnormalities can lead normal lives if raised in a healthy environment.
Tall stature is common and patients can show severe acne and infertility.
Intelligence is not affected compared to controls and siblings, and transmission to offspring is low. With XXY, the phenotype is unremarkable at birth but at puberty there is a spurt of growth, along with other signs such as female escutcheon and small testes. The vast majority of cases are diagnosed in adulthood. There is no effect on performance IQ but the verbal IQ can be affected. For more information, take a look here .