Atypical chromosome patterns - Klinefelters

Question 1

What is Klinefelters?

Answer 1

Chromosomal condition that affects male physical and cognitive development

Question 2

How many does Klinefelters affect?

Answer 2

1 in 750 males

Question 3

What is the genetic makeup of a male with Klinefelters?

Answer 3

XXY

Question 4

What physical effects does Klinefelters cause?

Answer 4

Small testes 
Produce insufficient amounts of testosterone
Inability to grow facial and pubic hair 
Develop breast tissue 
Low fertility 
Long arms and legs in relation to torso

Question 5

What psychological effects does Klinefelters cause?

Answer 5

Low masculinity
Poor language skills, affecting reading ability
Passive temperament
Attention problems
Increased risk of anxiety disorders and depression

Question 6

What is MKS?

Answer 6

Mosaic klinefelters syndrome

Having the extra X chromosome in only some of the cells

Question 7

How is Klinefelters caused?

Answer 7

Occurs during meiosis
Nondisjunction occurs which causes an egg and sperm to produce an extra copy of the X chromosome
Leads to the embryo at conception having an extra copy of the X chromosome

Question 8

What medical complications can arise from having Klinefelters?

Answer 8

Cardiovascular, circulatory and respiratory conditions
Diabetes
Renal problems

Question 9

What is treatment for Klinefelters?

Answer 9

Treated with testosterone supplements which allows them to live a relatively normal life

Question 10

What did Simpson et al (2003) find?

Answer 10

• Behavioural and language difficulties resulting from having KS could be successfully treated with androgen therapy.
• Greater improvements seen when it was treated earlier showing detrimental effects of KS can be successfully counteracted

Question 11

What did Swerdlow et al (2005) find?

Answer 11

• Investigated mortality in men with KS between 1959 and 2003 in the UK
• Finding that 461 of 3518 had died, higher than non-KS men
• Major causes of death were cardiovascular disease, respiratory, diabetes and epilepsy

Question 12

What did DeLisi et al (2005) find?

Answer 12

• subjected 11 KS participants and 11 non-KS participants to a psychiatric interview, cognitive tests and an MRI scan
• 10 of the KS males had some form of a psychiatric disturbance and generally KS sufferers had smaller frontal lobes, temporal lobes and superior temporal gyrus brain areas, affecting language
• Biological basis for the psychological effects of KS

Question 13

What did Stockholm et al (2012) find?

Answer 13

• Investigated criminal patterns in 1005 Danish men with standard KS and found that men with KS had higher conviction rates for sexual abuse, burglary and arson
• Lower convictions for traffic and drug offences than males without KS
• Socioeconomic variables were changed, such as class, conviction levels were similar
• Suggesting KS’s association with increased criminality may be due to poor conditions rather than the actual condition