Consult SID
Symptoms, Indicators and Diagnosis (SID)
Much of the information available about XXY/Klinefelter’s Syndrome is related to how it affects males because the syndrome was first identified in a group of males. Consequently, SID concentrates on the affect low or zero testosterone has on males. But as in the general population there are people who have XXY who do not consider themselves to be male; more research is needed to determine how XXY affects these people as they may require different medication, such as oestrogen in preference to testosterone. As that data becomes available the KSA will add to these pages. A newly created website that provides useful information for those who do not consider themselves male can be found at the XXY Brain Trust
In describing the symptoms associated with KS the KSA has used extracts from its Members Binder, from other KSA publications, desk based research and from polls conducted via the KSA’s international talk forum www.XXYTalk.com.
The KSA gratefully acknowledges the award of a grant from the British Society of Endocrinology without which the Consult SID pages would not have been feasible.
How does KS affect a man?
Klinefelter’s Syndrome (KS) is characterised by low testosterone levels as the testes do not function properly. Teenagers and young adults often have average to low levels but these decrease although some men may continue to have levels within the normal range.
Low testosterone causes decreased energy levels, low motivation and lack of muscle bulk and strength. There is a tendency to be overweight and female breasts may develop.
Not surprisingly, self-esteem is likely to be affected.That is the difference a lack of testosterone makes and is the reality of life for many men with KS because their bodies do not produce testosterone.
Those with KS are often labelled as lazy and lacking in intelligence. However findings from magnetic resonance imaging (MRI) studies in KS show structural abnormalities of brain regions which are connected to social understanding and emotion perception and which are related to language and communication impairments.
As language and communication affects all areas of learning and life it is not surprising that learning difficulties are common despite normal non-verbal IQ levels.
Those with KS are less able to identify and verbalise
the emotions they experience and are also less able to identify emotions when expressed in tone of voice. In addition they are often more emotional than is usual for men.
Again these difficulties appear to be linked to the abnormalities in some brain regions.
Klinefelter men appear to be less accurate in perception of social emotional cues such as identification of facial expressions and gaze direction. The lack of these skills will contribute to decreased social competence and difficulty establishing successful social interactions and in coping with social situations.

Symptoms
The symptoms of KS vary considerably between individuals. The severity of the condition can also be associated with the number of extra X sex chromosomes present.
- Very small testes/low levels of testosterone
- Infertility
- Low sex drive/libido
- Gynaecomastia (female type breasts)
- Poor social skills
- Low self-esteem
- Poor short term memory
- Difficulty processing verbal information
- Poor communication and organisational skills
- Unexplained tiredness or lethargy
- Tall stature with disproportionally long legs and arms
- Lacking or sparse body and facial hair
- ‘Female type’ body shape and fat distribution
- Flabby or poor muscle tone especially upper body
- Low bone density
- Varicose veins of the lower legs and poor circulation
- A predisposition to thrombosis
- Depression and mood swings
- Urinary tract infections
- Migraines
- Autoimmune disorders
- Osteoporosis
- Increased risk of breast cancer
- Speech and language development disorders
- Poor concentration skills
- Lack of agility and dislike of physical games, especially team games
- Passiveness/shyness
- Difficulty with self expression
- Moderate learning difficulties
Although low intelligence was once seen as a symptom it is more likely that the speech and language development disorders, in addition to the other symptoms listed above are the cause of the learning difficulties. Most of those with KS are within the normal intelligence range although they may require more targeted support and effort then their peers. A highly useful publication, available via the Free Downloads, is “The Learning Needs of Boys with KS: Information for Teachers and Parents” by Paul Collingridge.
Another point of view is that children diagnosed with KS develop at a slower rate than other children. To quote Onnineko of XXYTalk.com
"The development time of the typical person is very short. It is well known that a child learns both better and faster than an adult. An XXY child develops over a period considerably longer than an XY or XX child, about 8 more years. Society for 99% of the world believes that at 18, the child is mature. However, XXY children mature at about age 25. If we compare an XXY child at their point of relative maturity at age 25 to an 18 year old, the 25 year old child is significantly higher on intelligence tests."
Younger looking and acting than actual age | 299 |
Uncommonly gentle, caring, sharing, and intuitive | 288 |
Lower degree of self esteem | 275 |
Reduced facial hair – reduction in need to shave / reduced body hair | 266 |
Depression or tendency toward it | 260 |
Reduced muscle power and stamina | 250 |
Height taller than average (avg. is 5 ft. 10 in. for USA Caucasian males) | 248 |
Difficulty in concentrating | 244 |
Incomplete masculinisation; feminine, or pear shaped body and body hair distribution | 244 |
Introversion and frequently shy | 239 |
Infertility | 237 |
Taller than fathers and brothers | 235 |
Decreased serum testosterone levels | 232 |
Life-long soft skin | 230 |
Decreased libido | 215 |
Anxiety and neuroses | 214 |
Change in body shape – increased fat and breast development | 212 |
Abnormal body proportions (long legs, short trunk) | 211 |
Gynaecomastia now or in the past | 207 |
Preference for quiet games when as a child | 197 |
Restless sleep pattern | 196 |
Rounded shoulders and rounded hips | 192 |
Difficult to awaken in the mornings | 185 |
Behavioural problems, including aggression and non-participation in social activities | 178 |
Frustration-based outbursts | 175 |
Emotional and mental disorders | 150 |
Non lateral thinker — visual spatial thinker | 150 |
Obesity | 148 |
The inability to maintain long term friends | 142 |
Learning disabilities especially language difficulties | 138 |
Sexual confusion | 138 |
Smaller than average erect penis (avg. is approx. 14 cm — 2.54 cm = 1 inch) | 129 |
Hand tremors | 128 |
To some degree, euneuchoidal stature (arm span is usually 2 inches longer than height) | 119 |
Erectile dysfunction and/or impotence | 117 |
Gender confusion | 105 |
High cholesterol problems | 99 |
Decreased bone mineral density in adults | 96 |
Minor bony abnormalities e.g. in hands and elbows | 95 |
Attention Deficit disorder | 94 |
Inner anger, requiring anger management | 93 |
Motor skill issues | 89 |
Taurodontism with teeth having a thinning of the surface and enlargement of the pulp | 82 |
Sleep apnea | 79 |
Cardio-vascular problems | 67 |
Dyslexia (physical) | 65 |
Increased serum luteinizing hormone | 52 |
Increased serum follicle stimulating hormone | 50 |
Loss of sense of smell | 51 |
Intersex | 47 |
Osteoporosis – brittle bones resulting in fractures | 43 |
Adult onset diabetes mellitus | 30 |
Simian crease (single crease in the palm) | 24 |
Venous disease | 23 |
Benign Prostatic Hyperplasia | 16 |
Arteriosclerosis (hardening of the arteries) | 13 |
Autoimmune disorders such as lupus and Darier’s syndrome | 13 |
Epilepsy | 13 |
Myocardial Infarction after the age of 30 is common | 10 |