Klinefelter’s Syndrome – Facts, Causes, and Treatment.


Klinefelter’s Syndrome is a genetic disorder that affects males; this is due to when a male born with an extra copy of X chromosome, which causes infertility, low testosterone and other abnormalities such as breast development. This syndrome affects the testicular growth, results in smaller testicles and may cause reduced muscle mass, reduced facial and body hair. Men with Klinefelter syndrome produce little or no sperm production. This can be managed by assisted reproductive procedure and may make possible to become a father.


The syndrome was named after Harry Klinefelter, who, in 1942, worked with Fuller Albright and E. C. Reifenstein at Massachusetts General Hospital in Boston, Massachusetts, and first described it in the same year. The account given by Klinefelter came to be known as Klinefelter syndrome as his name appeared first on the published paper, and seminiferous tubule dysgenesis was no longer used. Considering the names of all three researchers, it is sometimes also called Klinefelter-Reifenstein-Albright syndrome.

The first published report of a man with a 47, XXY karyotype was by Patricia Jacobs and John Strong at Western General Hospital in Edinburgh, Scotland in 1959. This karyotype was found in a 24-year-old man who had signs of Klinefelter syndrome. Jacobs described her discovery of this first reported human or mammalian chromosome aneuploidy in her 1981 William Allan Memorial Award address.


This syndrome, evenly spread in all ethnic groups, has a prevalence of 1-2 subjects per every 1000 males in the general population. 3.1% of infertile males have Klinefelter syndrome. The syndrome is also the main cause of male hypogonadism.

According to 2008 meta-analysis, the prevalence of the syndrome has increased over the past decades; however, this does not appear to be related to the increased age of the mother at conception, as no increase was observed in the rates of other trisomies of sex chromosomes (XXX and XYY). The National Institutes of Health; however, state that older mothers might have a slightly increased risk.

Risk factors

  • Klinefelter syndrome stems from a random genetic event. The risk of Klinefelter syndrome isn’t increased by anything a parent does or doesn’t do.
  • For older mothers, the risk is higher but only slightly.

Causes of klinefelter’s Syndrome

Klinefelter occurs as the result of the error that occurs in chromosomes, that causes the male to born with an extra copy of sex chromosomes.

Normally, humans have 46 chromosomes, including sex chromosomes that determine the sex. Females have XX chromosomes and male have XY chromosomes.

Klinefelter syndrome is caused by:

  • Presence of extra X chromosome in male
  • It can occur when genetic material in sperm splits unevenly
  • It is not an inherited condition and it is not passed on to the parents. It occurs due to the error within in the fertilized egg or during the division of cells as the baby develops


The symptoms of Klinefelter syndrome vary between individuals. The symptoms that usually affects the young boys are learning and behavioral problems. Generally, small testes are present in all men with Klinefelter syndrome. The symptoms of Klinefelter Syndrome can be differentiated from their growing stages.


Puberty and Adulthood

Difficulties with speech and reading Fatigue
Lower attention span Depression
Behavioural problems Taller than average height
Undescended testes at birth (uncommon) Breast enlargement (gynecomastia)
Poor muscle tone Small testes
Delayed motor development Fat accumulation on hip and abdomen
Shyness and low self-confidence Poor erection and low libido
Mild dyslexia and/or dyspraxia Infertility
Low energy levels, Osteoporosis
Difficulty socializing or expressing feelings less growth of facial and body hair/decreased shaving frequency 

Effects of klinefelter’s syndrome

Men with Klinefelter syndrome are at increased risk of developing the serious health problems.

  • Male breast cancer
  • Osteoporosis
  • Cardiovascular disease and blood clots
  • Lung disease
  • Type 2 diabetes
  • Autoimmune disorders such as lupus
  • Hypothyroidism
  • Varicose veins
  • Infertility
  • Sexual dysfunction
  • Attention Deficit Hyperactivity Disorder (ADHD) in children

Diagnosis and Test

Klinefelter’s syndrome is diagnosed before birth while performing prenatal testing such as amniocentesis, chorionic villus sampling (CVS) and maternal blood test in early pregnancy. It is also diagnosed postnatally through a blood test.

During childhood, Klinefelter’s syndrome can be identified when the child feels difficulties in learning and behavior. In adulthood, the diagnosis of Klinefelter’s syndrome might not be made until the man seeks medical help for infertility, a loss of sex drive or a bone fracture, or is not diagnosed at all.

Physical examination: The doctor will do a genital examination to check the size of testes and will measure the height of the person.

Blood test: A diagnosis of Klinefelter’s syndrome is confirmed using a blood test called a karyotype that checks the number and structure of chromosomes in cells.

Hormone testing: Blood test is used to measure the levels of testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH).

  • LH is needed for the cells in the testes to make testosterone. Testosterone and FSH act together on the seminiferous tubules (sperm-producing tubes) in the testes to make sperm.
  • In men with Klinefelter’s syndrome, the LH levels are raised, but the testosterone levels are at the borderline and normal. FSH levels are also high, which is a symptom of damage to the seminiferous tubules in the testes.

Semen examination: Semen is examined for sperm count and fertility.

Treatment and medications

There is no complete cure for the Klinefelter syndrome, but there are certain corrective measures to make changes in aesthetic appearance and behavioral problems.

Breast reduction Surgery: In males with enlarged breast, plastic surgeon removes the excess breast tissue and leaving the chest to the normal look.

Testosterone replacement therapy (TRT): Testosterone is replaced into XXY males, which helps to develop bigger muscles, deepen the voice, and grow facial and body hair. TRT is often started when the XXY boy reaches the puberty. TRT involves taking medications that contain testosterone, which can be in the form of tablets, gel, and injection.

Educational support: some XXY boys have trouble in learning and socializing. As children, they can get assistance from their school teachers by using certain teaching methods in the classroom. One of such is tackling bigger tasks in an easier way.

Psychological counseling: People with Klinefelter’s syndrome have emotional issues because of their external appearance and behavior. A family therapist and counselor or psychologist can help work through the emotional issues.                              

Fertility treatment: Because few or no sperm produced in the XXY males, artificial insemination and Intra-cytoplasmic sperm injection (ICSI) may help to father a child. In this procedure, donor sperm is removed from the testicle using a biopsy needle and then injected directly into the egg.

Physical and speech therapy: These therapies help the boys with Klinefelter’s syndrome to make a proper speech, good in language and to recover muscle weakness.

Prevention of klinefelter’s syndrome

  • In the current scenario, there is no prevention of Klinefelter’s syndrome because this condition is due to genetic mutation occurs during fertilization of eggs.
  • Mother with Klinefelter’s syndrome child in earlier should go for the genetic test before conceiving a second baby.
  • As it is believed that the women conceiving at the age of 35 or after 35 are at higher risk of having a child with Klinefelter’s syndrome. So it is advisable for a couple to plan for a child before age of 35.

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  1. where can
    I get help. especially if I feel I may have such symptoms

  2. diagnosed, 2008, born 1964.
    having difficulty with ignorant person’s, including medical person’s. Suffered, a chronic heart attack ,August 2016. Treated, flushed my heart arteries, still not well, very worried….

  3. sir i am 21 years old have no beard and shrill voice

  4. Fwatted Arbak Samuel

    Small testicular size, quick ejaculation, poor beard development, long arms and legs. These symptoms are obvious with me. Am around mid thirties now and really want to marry but afraid of my condition. Need help pls.

  5. ihave no brain growth and socially not interact other persons
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