Klinefelter Syndrome

Klinefelter Syndrome often referred to as XXY trisomy, XXY syndrome, and Klinefelter’s Syndrome is a chromosomal disorder exclusively associated with males having one or more of the X chromosome than the normal ‘XY’ pattern. The symptoms of this condition which impedes cognitive and physical development vary from one affected person to another. The more the number of X chromosomes in the majority of cells, the greater is the severity of the symptoms.

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This chromosomal condition was first observed and documented by Harry Fitch Klinefelter Jr, an American endocrinologist, and rheumatologist in the 40s, and hence its name. Individuals with KS usually have small testicles and are unable to father children. Inability to produce a sufficient amount of testosterone, inordinate tallness, weak muscles, and poor motor coordination are some of the strong indicators of this disorder.

Klinefelter Incidence

Affecting 1 out of every 500-1000 male neonates, Klinefelter syndrome is a somewhat widespread chromosomal aberration affecting humans. However, variants of this condition are relatively rarer, prevalent in just 1 out of every 50,000 newborns. Symptoms of KS generally turn out to be noticeable with the onset of puberty and become pronounced as the individuals attain adulthood.

Just because you have an additional X chromosome, does not imply that you’ll invariably demonstrate the usual symptoms. You’ll be more susceptible to exhibiting the signs (and hence vulnerable to being diagnosed with KS) if a higher proportion of cells have the extra chromosome, testosterone levels are abnormally low, and you’re on the threshold of puberty. There is no known cure for treating the disorder neither is any treatment available which can correct the anomalous chromosome pattern.

Fortunately, there are numerous treatment plans that can help individuals with KS lead an almost normal life as well as live as long as those who are unaffected by the syndrome.

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Klinefelter’s Syndrome Symptoms

Whether an individual having KS will show nearly all the symptoms related to the condition or just a few, depends on the factors mentioned above. While symptoms start emerging in some males much before puberty, most of them are affected when they reach their teens. Some experience the first signs when they become adults, but there are many who never feel the symptoms.

The symptoms make their presence felt in chiefly three areas associated with growth and progress-fine motor skills, gross motor skills, and physical development.

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Klinefelter’s Syndrome Symptoms in Newborns

  • Testicles have not settled inside the scrotum (a condition known as cryptorchidism)
  • A hernia
  • Weak muscles
  • Delayed speech cognition, and slow in sitting, crawling or standing
  • Taller than their peers at or after four years of age

Klinefelter’s Syndrome Symptoms in Infants

  • Reduced energy levels
  • Delayed cognitive development
  • Low self-esteem
  • Shyness

Klinefelter’s Syndrome Symptoms in Adolescents

  • Development of breasts like the opposite sex
  • Unusually tall, normally taller than siblings, cousins or friends
  • Firm and small testes
  • Small penis
  • Short torso, wide hips, and longer limbs in proportion to the entire body
  • Retarded muscle growth and low muscle tone
  • Lesser hairs on the face, chest, and other parts of the body compared to other male teenagers

Klinefelter’s Syndrome Symptoms in Adults

  • Low sexual desire
  • Infertility (low sperm count)
  • Erectile dysfunction (Difficulty in having or maintaining an erection)


Klinefelter Syndrome Causes

Male babies born with atypical cell chromosomal pattern (where they’re more than one X chromosome) are at greater risk of demonstrating KS symptoms. Klinefelter syndrome is not a genetic or hereditary condition but transpires due to a randomized error in chromosomal patterning. A human is born with 23 pairs of chromosomes or 46 chromosomes in total.

One of these pairs happens to be the sex chromosomes that go on to determine whether the unborn individual will be a male or female. The sex chromosome pattern of males is XY while that of females is XX.

Klinefelter syndrome occurs when:

  • One extra X chromosome in all or most of the cells (XXY) (most prevalent)
  • Multiple X chromosomes in the majority of the cells (say XXXY) (very severe form but very rare)
  • Additional X chromosome in a small proportion of cells

Does Klinefelter Syndrome make one vulnerable to other health issues?

It is worthwhile to note that less than normal testosterone production is mainly behind the various problems attributable to Klinefelter Syndrome. Those with KS could be prone to developing:

  • Chronic obstructive pulmonary disease (COPD)
  • Breast cancer
  • Cancers related to lymph nodes, bone marrow, and blood
  • Autoimmune disorders, including but not limited to rheumatoid arthritis, SLE (systemic lupus erythematosus), multiple sclerosis, and ankylosing spondylitis
  • Hormonal disorders like diabetes, thyroid, and Cushing’s disease to name a few
  • Complications associated with blood vessels like deep vein thrombosis, varicose veins, and Paget-Schroetter syndrome
  • Osteoporosis or fragile bones
  • Depression, anxiety disorder, and other mental health issues

Klinefelter Syndrome Diagnostic Tests

When you consult a physician for confirming the disorder, he or she will first do a routine physical exam. The doctor will review the medical history, inquire about your health, and will want to know the symptoms you are having. After that, the physician will examine your testicles and penis as well as check your chest. He may also perform a few ordinary tests. However, the general practitioner will invariably carry out two crucial for accurately diagnosing KS:

  • Hormonal assays: Hormone tests determine levels of the hormone in urine or blood.
  • Chromosomal or genetic analysis: A special type of blood test that analyzes your chromosomes. This test is also known as ‘karyotype analysis’.

Klinefelter Syndrome Treatment

Klinefelter Syndrome is not curable. However, there are treatment options that could help manage the disorder, they include:

  • Testosterone replacement therapy (Can start during puberty and needs to be taken throughout the lifetime)
  • Fertility treatment
  • Physical therapy and occupational therapy
  • Language therapy
  • Social skills therapy
  • Surgery for reducing breasts

Affected children should be encouraged to participate in group games and activities for stimulating holistic physical and mental development.

Klinefelter Syndrome Picture

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