Atypical sex chromosome patterns

Question 1

What is atypical sex chromsome patterns?

Answer 1

• Any sex chromosome that deviates from the usual XX or XY formation which tends to be associated with a distinct pattern of physical and psychological symptoms

Question 2

Describe klinefelters syndrome

Answer 2

• Klinefelters syndrome is an example of an atypical sex chromsome pattern
• it affects one in 600 males
• individuals with this condition are anatomically males but have an additional X chromosome
• Therefore their sex chromosome structure is XXY
• Although 10% of cases are identified by prenatal diagnosis, it is thought 2/3 of people have klinefelters syndrome and are unaware of it
• diagnosis is normally accidental

Question 3

What are the physical characteristics of klinefelters syndrome

Answer 3

• One of the effects of having XXY chromosomes is that there may be some breast development at puberty (gynaecomastia) and a softening or rounding of body contours
• long, gangly limbs
• underdeveloped genitals
• reduced body hair
• problems with co - ordination and clumsiness
• susceptible to health issues such as breast cancer

Question 4

What are the psychological characteristics of klinefelters syndrome

Answer 4

• linked to poorly developed language skills, reading ability and tend to be passive, shy and lack interest in sexual activity
• tend to not perform well with stressful situations and struggle with executive functions such as memory and problem solving

Question 5

What is an overview of turners syndrome

Answer 5

• A chromosomal disorder in which affected women only have one X chromosome (X0), causing developmental abnormalities and infertility
• This affects 1 in 5000 biological females
• affected individuals have 45 chromosomes instead of 46

Question 6

What are the physical characteristics of turners syndrome

Answer 6

• individuals with turners syndrome do not have a menstrual cycle as their ovaries do not develop and thus they are infertile
• they do not develop breasts and have broad shield chests
• they have low set ears and a webbed neck
• they have a high waist to hip ratio so their hips are not much bigger than their waist
• typically, they favour prepubescent girls

Question 7

What are the psychological characteristics of turners syndrome

Answer 7

• higher than average reading ability
  -lower than average spatial, visual and mathematical skills
• tend to be more socially immature, having trouble fitting in

Question 8

What is a strength of atypical sex chromsome patterns?

Answer 8

• the nature - nurture debate
• one strength is that it contributes to the nature - nurture debate. By comparing people with syndromes with chromsome typical individuals, it becomes possible to see the different psychological and behavioural differences between the two groups
• for example, individuals with turners syndrome have higher reading ability. These differences are purely as a result of different chromosomal structures. This supports nature
  Counterpoint: These differences could be due to nurture. For example, social immaturity in females with turners syndrome may be due to being treated immaturely by people. People may react to the prepubescent appearance of people with turners syndrome in a way that encourages immaturity, which could also impact their performance at school

Question 9

What is another strength

Answer 9

• real world applications.
• continued research into atypical sex chromosomal patterns is likely to lead to more accurate diagnosis of klinefelters and turners syndrome and more positive outcomes
• An australian study of 87 individuals with klinefelters syndrome showed that individuals who had been diagnosed earlier had significant benefits in managing their syndrome
• this shows that increasing awareness of atypical sex chromosome patterns has real world applications so those with these syndromes can get the correct help

Question 10

What is a limitation of this

Answer 10

• one limitation of description of klinefelters syndrome is that there is a small sample size
• to identify characteristics of XXY it is necessary to identify a large database of people with these syndromes
  -However, for those who have been identified have the most severe symptoms therefore the typical symptoms have been distorted
• Boada said that prospective studies are more accurate for klinefelters and turners syndrome as many do not experience cognitive and psychological issues, many are very successful
• this shows that symptoms may be exaggerated