A01

• What are two atypical sex chromosome patterns?

  • Klinefelter’s syndrome
  • Turner’s syndrome
• What is Klinefelter’s syndrome?

  An abnormal / atypical chromosome pattern in males, where there is an extra X chromosome (XXY configuration)
• How common is Klinefelter’s syndrome?

  Around 1 in 500 to 1 in 1000 males are affected
• What are the physical differences for Klinefelter’s syndrome?

  • Taller than average
  • Longer limbs
  • Reduced body hair
  • Breast development
  • Underdeveloped genitalia
  • Less muscular coordination
  • Often infertile
• What are the psychological / developmental differences for Klinefelter’s syndrome?

  • Poorly developed language and reading skills
  • Passive and shy temperament
  • Poor memory and problem-solving skills
  • Lack interest in sexual activity
• What medical complications can arise for those suffering with Klinefelter’s syndrome?

  XXY men are more susceptible to health problems that commonly affect females, such as breast cancer
• What is Turner’s syndrome?

  An abnormal / atypical chromosome pattern in females, where there is only one X chromosome (XO configuration) meaning affected females only have 45 chromosomes
• How common is Turner’s syndrome?

  Around 1 in 2200 females are affected
• What are the physical differences for Turner’s syndrome?

  • Shorter than average
  • High waist-to-hip ratio
  • No breast development
  • Webbed neck
  • Broad, ‘shield-like’ chest
  • Underdeveloped ovaries, resulting in lack of / no menstrual cycle and possible infertility
• What are the psychological / developmental differences for Turner’s syndrome?

  • Higher than average reading ability
  • Poor spatial, visual and mathematical skills
  • Socially immature - have trouble ‘fitting in’
• What medical complications can arise for those suffering with Turner’s syndrome?

  Heart conditions, high blood pressure, urinary complaints, vision and hearing problems and osteoporosis