Atypical Sex Chromosome Patterns

• Klinefelter’s Syndrome

  affects ~ 1 in 750 males, involves having an extra X chromosome (XXY)

  males with condition have: small testes that produce insufficient amount of testosterone before birth and during puberty - normal male sexual characteristics do not develop

  physical effects = lack the ability to grow facial and pubic hair; have broader hips; develop breast tissue; have low fertility levels
• ao3 Klinefelter’s - delisi et al (2005)

  11 KS ppts and 11 non-KS controls to psychiatric interview, cognitive tests and MRI scan

  10/11 KS males had some form of psychiatric disturbance, generally: KS males had smaller frontal and temporal lobes - might explain the language defects in KS ppts
• ao3 Klinefelter’s - stocholm et al (2012)

  investigated criminal patterns in 1005 Danish men:

  found KS men had higher conviction rates for sexual abuse, burglary and arson

  
  

  however, socioeconomic adjustments were made - convictions were then similar to controls
• Turner’s Syndrome

  genetic condition that affects ~ 1 in 2200 females, involves having only one complete X chromosome (XO)

  physical effects: short stature; down-slanting eyes; broad chest; lots of moles; organ abnormalities

  main deficiency is non-functioning ovaries, results in girls with TS not developing breasts, having periods and being infertile
• ao3 Turner’s - Brown et al (2002)

  performed MRI scans on 26 girls with TS and 26 gender and age matched non TS girls - girls with TS had smaller posterior cerebral and cerebellar brain areas

  there were no differences between TS girls who has a maternally inherited or paternally inherited X chromosome
• ao3 - evaluating both KS and TS

  can be diagnosed prenatally

  however, ethically and socially sensitive - diagnosis may incur a demand for or pressure upon parents to ask for an abortion