In the world of science, biological sex is determined by the type of sex chromosomes a person has. These hormones are important as they allow a female to produce enough estrogen to develop wide hips and a male to produce enough testosterone to grow facial hair.
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Team Klinefelter and Turner Syndrome Teachers
But what happens when a biological male has an extra X chromosome (Klinefelter syndrome), and a biological female is missing an X chromosome (Turner syndrome)? Klinefelter and Turner’s syndromes are fascinating phenomena that researchers of various fields, including psychology, have sought to study.
Before diving into Klinefelter and Turner Syndrome in psychology, let’s be sure we know what a sex chromosome is.
Chromosomes hold vital genetic information in the form of genes, and they exist throughout the body in the cells. As you may know, humans have 23 chromosomes; typically, a person having either XX chromosomes (female) or XY chromosomes (male) determines their sex.
However, some syndromes can affect these sex chromosomes, causing many issues for those involved, known as atypical sex chromosome patterns (Klinefelter and Turner syndrome).
Atypical sex chromosome patterns: occurs when sex hormones deviate from the typical XX/XY formations, which give us male or female characteristics.
Although 10% of cases are diagnosed prenatally, two-thirds of people with the condition are unaware they have Klinefelter’s Syndrome. In such cases, a diagnosis is often made due to another health condition.
Klinefelter’s Syndrome is when biologically male people (anatomically appear male) have an extra X chromosome, making their chromosome pattern XXY.
Individuals with Klinefelter Syndrome show reduced volume in several brain areas, including the amygdala, temporal and frontal regions, hippocampus, and insular cortex. On the other hand, they show increased volume in the sensorimotor and posterior-occipital areas of the brain.
What makes Turner’s Syndrome different?
Turner’s Syndrome occurs in biological females who lack an X chromosome, i.e., Turner’s syndrome patients have 45 chromosomes rather than the usual 46.
Fig. 1 Blood testing for DNA is used to diagnose Klinefelter Syndrome and Turner Syndrome.
Turner Syndrome and Klinefelter Syndrome symptoms present quite differently from one another.
So how exactly does an extra X chromosome affect males? Klinefelter syndrome has physical, psychological, and behavioural symptoms.
Reduced body hair.
Slim physique.
Tall.
Gynecomastia (breast development at puberty)
Softening of body contours.
Broad hips.
Long limbs.
Underdeveloped genitals.
Coordination problems (neuro-dyspraxia).
Clumsiness.
More susceptible to typically female illnesses such as breast cancer.
Poorly developed reading and language skills.
Passivity.
Shyness.
Lack of interest in sexual activity, infertility.
Inability to cope with stress.
Problems with executive functions such as memory and problem-solving.
How does a missing X chromosome affect a female? Here are the symptoms of Turner syndrome.
Amenorrhoea: a lack of menstrual cycle due to their ovaries failing to develop.
Lack of breast development leaves them with a broad ‘shield’ chest.
Low-set ears.
‘Webbed neck’ (an area of folded skin that goes from the ears to the neck)
Low waist-to-hip ratio. Hips are not much bigger than the waist.
Physically immature, appearing prepubescent.
Shortness.
Upturned nails
Above-average reading ability.
Reduced spatial, mathematical, and visual memory skills.
Socially immaturity.
Difficulty fitting in.
The existence of genetically atypical individuals means we can determine whether gender differences have a genetic basis. We can compare these individuals with chromosome-typical people. If we see psychological or physical differences between the two groups, we can infer this results from genetic differences.
Diagnosis of both syndromes assumes ‘typical’ gender behaviours.
For example, stating that shy men are atypical suggests that confidence is a male characteristic, upholding societal views of a ‘typical male’.
These assumptions could be problematic because the definitions of both syndromes use socially established gender norms to diagnose people with medical conditions.
Another important note is that the differences between people with atypical and typical chromosome patterns are not causal. Therefore, other factors could influence this, such as environmental or social influences.
For example, the social immaturity cited as a symptom of Turner’s Syndrome could result from women with the condition being treated as younger than they are due to their immature appearance. If they look youthful, this could lead to educational problems as teachers and parents may treat them as younger and less educated than others.
Therefore, it is wrong to assume that all the symptoms associated with both syndromes are purely a result of atypical chromosome patterns, as the environment could influence them.
Unfortunately, Klinefelter’s Syndrome has no cure. However, physicians may focus on reducing the symptoms and effects of associated conditions using techniques and treatments such as:
Testosterone Replacement Therapy
Occupational Therapy
Physiotherapy
Educational and behavioural support
Breast reduction therapy
Let’s look at what a few of these treatments might look like.
Especially during adolescence, testosterone plays a crucial role in development as it’s known to help organise the brain and behaviour. Boys diagnosed with Klinefelter syndrome who underwent testosterone replacement treatment with low doses of androgen showed improvements in social functioning, visual-motor functioning, and anxiety.
TRT has also been associated with increasing hippocampal size and reducing depressive symptoms.
Better yet, early hormone therapy (EHT) during infancy is effective in helping boys with Klinefelter syndrome improve speech and language development, reading skills, and neuromotor planning and execution. It has also been shown effective in reducing behavioural problems such as aggressive behaviours, externalising behaviour issues, and schooling behaviour.
Fig. 2 Testosterone replacement therapy is often administered by injection.
Neuro-dyspraxia is a unique symptom that can occur for some individuals with Klinefelter syndrome.
Neurodyspraxia: a neurological disorder that impacts a person’s ability to plan and execute motor movements.
Occupational therapy is a common way of treating this particular condition. Klinefelter syndrome patients with this condition undergo rehabilitation with an occupational therapist who walks them through various exercises.
“The Good Start Method” is an example of the exercises one might undergo with an occupational therapist.
This method asks the patient to copy graphical images in synch with musical rhythms. The idea is for this to help stimulate motor activity. The task becomes more complex as they go along.
Can Klinefelter’s Syndrome impact a person’s life expectancy? Sadly, it can -- but not by much. Mortality rates of men with this diagnosis are 50% higher than the average male. Still, one can expect the Klinefelter syndrome life expectancy to be around 2-5 years old shorter than the average male.
The leading causes of death associated with Klinefelter’s Syndrome are:
Cerebrovascular disease.
Subarachnoid haemorrhage.
Carcinoma of the breasts.
Aortic valve disease.
Other health issues associated with Klinefelter’s Syndrome include:
Here are a few more interesting facts about Turner syndrome.
1 in 2000 girls will be diagnosed with Turner syndrome. Women with Turner syndrome often have fertility issues. And while spontaneous pregnancies may happen, they often carry major risks.
Pregnant women with Turner syndrome are 100x more likely to die than other women.
Similar to Klinefelter syndrome, Turner syndrome does not have a cure. Rather than receiving TRT like those with Klinefelter syndrome, women with Turner syndrome often undergo estrogen replacement therapy. They may also receive growth hormones to aid in increasing their short stature.
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What is the difference between Klinefelter’s syndrome and Turner’s syndrome?
Klinefelter’s syndrome is where males have an extra X chromosome: XXY. Turner’s syndrome is where females lack an X chromosome.
What combination of sex chromosomes results in Turner’s syndrome?
Turner’s syndrome is where a female has a missing or altered X chromosome. So, they will have an X chromosome instead of the usual XX.
What is the cause of chromosomal abnormalities such as Klinefelter’s and Turner’s syndrome?
Causes can vary. Typically, however, it is due to the chromosomes being affected during the formation of reproductive cells (sperm and egg). For instance, nondisjunction prevents the proper distribution of X chromosomes.
What chromosome abnormality is associated with Klinefelter’s syndrome?
The chromosome abnormality in Klinefelter syndrome is an additional X chromosome, so males have XXY chromosomes instead of the typical XY.
Is the Klinefelter syndrome recessive or dominant?
The Klinefelter syndrome is not inherited, so it is neither recessive nor dominant.
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