Atypical Sex chromosome patterns

• Kleinfelter’s syndrome and Turners sydrome are chromosomal patterns which occur randomly during fusion of egg and sperm and are not inherited genetically.
• Klinefelters syndrome - affects males who have a chromosomal abnormality with three sex chromosomes - XXY

  Affects 1 in 500 to 1000
• Klinefelter syndrome physical symptoms:

  • Taller than average
  • Weaker muscles
  • Reduced body hair
  • Rounder body shape
  • Smaller testes
  • Infertile
• Klinefelter syndrome psychological symptoms:

  • Low sex drive
  • Poor verbal skills
  • Difficulty coping with stress
  • Weak memory and problem solving
• Turner’s syndrome - abnormality affecting girls caused by having only one X chromosome rather than two.

  Affects 1 in 5000 females
• Turner syndrome physical symptoms:

  • Shorter than average
  • Normal genitalia but ovaries do not develop
  • No periods
  • Infertile
  • Webbed neck
  • Do not develop breasts
• Turner syndrome psychological symtoms:

  • Superior reading ability
  • Poor spatial and mathematical skills
  • Poor social skills
• AO3 - contribution to nature nurture debate

  Comparing people who have these conditions with typical chromosomes becomes possible to see psychological and behaviour differences between the two groups. Suggesting these differences have a biological basis and innate influences have a powerful effect on psychology.
• AO3 - practical applications

  Continued research is likely to lead to earlier and more accurate diagnosis of both syndromes, leading to better outcomes in the future.

  Herlihy found 87 males with KS, those who had been diagnosed at a young age had better benefits than those diagnosed in adulthood.
• AO3 - criticism

  The assumption that everyone develops the associated chromosomes. Research into both syndromes can be criticised for ignoring individual differences. Some males develop mosaic klinefelter syndrome which is when additional X chromosome appears only in some cells.

  Suggests that when diagnosing, researchers must considea variations of the condition and avoid assuming everyone will have the same characteristics.