A01

• How many males are affected by Klinefelter's syndrome?

  About 1 in 600 males
• What is the sex chromosome structure of individuals with Klinefelter's syndrome?

  XXY
• How are most cases of Klinefelter's syndrome diagnosed?

  Accidentally via unrelated medical examination
• What percentage of Klinefelter's syndrome cases are identified prenatally?

  About 10%
• What are the physical characteristics of Klinefelter's syndrome?

  • Reduced body hair compared to XY males
  • Possible breast development (gynaecomastia)
  • Softening or rounding of body contours
  • Long gangly limbs
  • Underdeveloped genitals
  • Coordination problems and clumsiness
  • Susceptibility to female health issues like breast cancer
• What are the psychological characteristics of Klinefelter's syndrome?

  • Poorly developed language skills
  • Low reading ability
  • Passive and shy behavior
  • Lack of interest in sexual activity
  • Difficulty responding to stress
  • Problems with executive functions (memory, problem-solving)
• What is Turner's syndrome caused by?

  An absence of one X chromosome
• How many chromosomes do individuals with Turner's syndrome have?

  45 chromosomes
• What are the physical characteristics of Turner's syndrome?

  • No menstrual cycle (amenorrhoea)
  • Infertility due to undeveloped ovaries
  • No breast development at puberty
  • Broad 'shield' chest
  • Low set ears
  • Webbed neck
  • High waist-to-hip ratio
  • Physically immature appearance
• How does Turner's syndrome affect reading ability?

  Higher-than-average reading ability
• What is often lower than average in individuals with Turner's syndrome?

  Spatial, visual memory, and mathematical tasks
• What are the social characteristics of individuals with Turner's syndrome?

  • Socially immature
  • Trouble relating to peers
  • Difficulty fitting in