A01

• Klinefelter's syndrome is an atypical sex chromosome pattern affecting about 1 in 600 males, characterised by an additional X chromosome (XXY). Physically, individuals with Klinefelter's syndrome often exhibit reduced body hair, underdeveloped genitals, and coordination issues. They are also prone to health problems more common in females, such as breast cancer.
• Psychologically, Klinefelter's syndrome is associated with underdeveloped language skills and reading ability. Individuals tend to be passive, shy, and have low sexual interest. They struggle with stress and executive functions like memory and problem-solving.
• Turner's syndrome affects approximately 1 in 5000 biological females and is caused by the absence of one X chromosome (XO), resulting in 45 chromosomes. Physically, individuals with Turner's syndrome do not menstruate, are infertile, and lack breast development. They often have a broad chest and a high waist-to-hip ratio, retaining a prepubescent appearance.
• Psychologically, individuals with Turner's syndrome generally have higher-than-average reading ability but lower performance in spatial, visual memory, and mathematical tasks. They tend to be socially immature, have trouble relating to peers, and often struggle to fit in.