atypical sex chromosome patterns

• ao1: Klinefelter’s syndrome

  • About 1 in 600 males have Klinefelter's syndrome
  • Individuals who have this condition are biological malesw male anatomy but have an additional X chromosome
  • 10% of cases are identified prenatally but up to 66% may not be aware of it. Diagnosis often comes about accidentally via a medical examination for some unrelated condition.
• ao1: klinefelter’s syndrome

  Some physical effects of XXY chromosome structure are:

  • Reduced body hair compared to a typical male
  • Some breast development at puberty (gynaecomastia)
  • Underdeveloped genitals.
  • More susceptible to health problems that are usually associated with females, such as breast cancer
• ao1: klinefelter’s syndrome

  Klinefelter's syndrome is often linked to psychological characteristics such as:

  • Poorly developed language skills and reading ability
  • Passive, shy and lacking interest in sexual activity
  • Tend not to respond well to stressful situations.
  • Problems with what are called executive functions, such as problem-solving
• ao1: turner’s syndrome

  • 1 in 5000 females have Turner's syndrome.
  • Caused by an absence of one of the two X chromosomes leading to 45 rather than 46 chromosomes
• ao1: Turner’s syndrome

  Individuals with Turner's syndrome have the following physical characteristics:

  • No menstrual cycle as their ovaries fail to develop, leaving them sterile.
  • A broad 'shield' chest and no developing of breasts at puberty.
  • Characteristic low-set ears and a 'webbed' neck
  • Hips are not much bigger than the waist.
• ao1: turner’s syndrome

  Psychological characteristics of Turner's syndrome include:

  • Higher-than-average reading ability.
  • Lower-than-average performance on spatial, visual memory and mathematical tasks.
  • Tendency to be socially immature.
• ao3: One strength of the research is its contribution to the nature-nurture debate.

  • Comparing both chromosome-typical and atypical individuals highlights psychological and behavioural differences. For example, Turner's syndrome is associated with higher verbal ability.
  • It might be logically inferred that these differences have a biological basis and are a direct result of the abnormal chromosomal structure.
  • This would suggest that innate 'nature influences have a powerful effect on psychology and behaviour.
• ao3: counterpoint to nature nurture debate

  • However, behavioural differences may result from social influences. Social immaturity in Turner's may be because individuals are treated that way due to their immature appearance.
  • This shows that it could be wrong to assume that psychological and behavioural differences in people with atypical sex chromosome patterns are due to nature.
• ao3: Another strength of research is its application to managing the conditions.

  • Continued researchto atypical sex romosome patterns leads to earlier and more accurate diagnoses and positive outcomes.
  • A study of 87 individuals with Klinefelter's syndrome showed that those identified when young benefitted in terms of managing their condition (Herlihy et al. 2011).
  • This suggests that increased awareness of these conditions has real-world application.
• ao3: One limitation is there may be a sampling issue.

  • Generally, only those people who have the most severe symptoms are included in the Klinefelter's database, therefore the typical profile may be distorted.
  • The use of prospective studies show the majority of those with Klinefelter's don't have cognitive or psychological problems, and many are highly successful (Boada et al. 2009).
  • This suggests that the typicalpicture of Klinefelter's (and Turner's) syndrome may be exaggerated