To investigate the criminal pattern in men between 15 and 70 years of age diagnosed with 47,XXY (Klinefelter's syndrome (KS)) or 47,XYY compared to the general population.
Register-based cohort study comparing the incidence of convictions among men with KS and with 47,XYY with age- and calendar-matched samples of the general population. Crime was classified into eight types (sexual abuse, homicide, burglary, violence, traffic, drug-related, arson and ‘others’).
All men diagnosed with KS (N=934) or 47,XYY (N=161) at risk and their age- and calendar-time-matched controls (N=88 979 and 15 356, respectively).
The incidence of convictions was increased in men with KS (omitting traffic offenses) compared to controls with a HR of 1.40 (95% CI 1.23 to 1.59, p<0.001), with significant increases in sexual abuse, burglary, arson and ‘others’, but with a decreased risk of traffic and drug-related offenses. The incidence of convictions was significantly increased among men with 47,XYY compared to controls with a HR of 1.42 (95% CI 1.14 to 1.77, p<0.005) in all crime types, except drug-related crimes and traffic. Adjusting for socioeconomic variables (education, fatherhood, retirement and cohabitation) reduced the total HR for both KS and 47,XYY to levels similar to controls, while some specific crime types (sexual abuse, arson, etc) remained increased.
The overall risk of conviction (excluding traffic offenses) was moderately increased in men with 47,XYY or KS; however, it was similar to controls when adjusting for socioeconomic parameters. Convictions for sexual abuse, burglary, arson and ‘others’ were significantly increased. The increased risk of convictions may be partly or fully explained by the poor socioeconomic conditions related to the chromosome aberrations.
To investigate crime rates of men with an extra sex chromosome (47,XXY and 47,XYY). Based on previous small studies, we hypothesised that an increased crime rate would be present in men with an extra sex chromosome and investigated this in a nationwide registry study.
Using a nationwide approach, we show that men diagnosed with KS (47,XXY) and 47,XYY are more frequently convicted for sexual abuse, burglary, arson and other reasons. Traffic offenses are seen less frequently in both groups.
Whether early diagnosis and improved clinical care can lead to a decrease in convictions is not clear.
The increased crime rate may be partly or fully mediated by poor socioeconomic conditions.
Strengths and limitations of this study
The study clearly delineates a pattern of increased crime rates among men diagnosed with an extra sex chromosome. The strength of the present study is the large number of men with sex chromosomes and the large control group and the merging of several registries.
The limitations are that we were not able to control for concomitant medicinal use, especially testosterone use in KS, nor to include clinical data.