What is Klinefelter Syndrome
Klinefelter syndrome is a genetic disorder caused by having an extra X chromosome in males (so males are XXY instead of XY) that can have a profound effect on the life of the person who has Klinefelter syndrome
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This results in stunted or delayed puberty, smaller than average genitals, and the development of breasts and infertility. Many men with Klinefelter syndrome will lead a normal life and don’t show any of the many noticeable symptoms until they are being investigated for infertility when they try to start a family.
Some have psychological problems such as depression, attention deficit disorder, schizophrenia, alcoholism, and other behavioral disorders.
How was Klinefelter syndrome discovered?
Klinefelter syndrome was described in 1942 by Harry F. Klinefelter when he and his co-workers discovered the combination of women’s features found in males. In 1956 was discovered Klinefelter syndrome was caused by the presence of two X chromosomes and one Y chromosome.
How often does Klinefelter syndrome occur?
Klinefelter syndrome affects one in 500 to 1,000 males.
Why does Klinefelter Syndrome Only Affect Males?
People who have XX develop into a female phenotype. People who have XY develop into a male phenotype. People who have XXY don’t fit in either category, but the genes that they do have cause them to develop into what is similar to a normal male phenotype, so we call them male. “Phenotype” is the observable traits of an organism. Men with Klinefelter have some female characteristics including wider hips and more breast development compared to other males. Most males with XXY can’t be distinguished from XY males in any noticeable way.
Which Parent Causes Klinefelter Syndrome?
Normally the mother passes an X chromosome to her offspring. Dad can pass either an X chromosome or a Y chromosome. This gives us XX (female) or XY (male) as the two options. In Klinefelter syndrome, the extra X chromosome can come from either the mother or the father. The extra X chromosome is the result of a spontaneous mutation that occurs during the creation of the reproductive cells. Thus, it is not an inherited condition.
Can a Man with Klinefelter Syndrome Have Babies Naturally?
We probably should rephrase the question to can a man with Klinefelter syndrome father babies naturally? In short, usually “no”.
Most men with Klinefelter syndrome are infertile and are unable to father children the usual way. But some can successfully father children once they begin taking testosterone treatment. In vitro fertilization is also an option following testicular sperm extraction (TESE)
Why does Klinefelter syndrome cause infertility? / How does Klinefelter syndrome affect fertility?
Klinefelter syndrome is the most common genetic condition associated with male infertility.
Infertility is defined as a failure to conceive after one year of unprotected sexual intercourse and is estimated to affect up to 15% of couples worldwide with a male factor implicated in approximately 50% of cases. Male infertility can manifest from numerous etiologies ranging from obstruction of the vasa deferentia to non-obstructive etiologies, such as genetic anomalies resulting in testicular dysfunction. Infertility in Klinefelter is a non-obstructive type.
There is progressive testicular dysfunction in Klinefelter syndrome. There are fewer germ cells to produce sperm. About 90% of males with Klinefelter have severe spermatogenesis impairment (unable to produce enough sperm).
What are some of Klinefelter syndrome’s facial and body features?
Signs and symptoms seen in Klinefelter syndrome include:
- Taller than average stature
- Longer legs, shorter torso, and broader hips compared with other boys
- Absent, delayed, or incomplete puberty
- Less muscle and less facial and body hair compared with other teens after puberty
- Small and firm testicles
- Small penis
- Enlarged breast tissue (gynecomastia)
- Weak bones (due to low testosterone levels)
Increased body fat.
Can someone with Klinefelter syndrome have a beard?
Due to low testosterone levels associated with Klinefelter syndrome those with Klinefelter grow little facial hair making growing a beard difficult without testosterone replacement therapy.
Do people with Klinefelter syndrome have body hair?
The answer to this is the same as the above question. Due to low testosterone levels associated with Klinefelter syndrome those with Klinefelter grow little facial hair making growing a beard difficult without testosterone replacement therapy.
Does Klinefelter Syndrome cause dental problems?
Some individuals with Klinefelter syndrome report dental issues. About half the individuals have taurodontism where the teeth have larger than normal chambers for holding the pulp made up of soft tissue and nerve endings thus having shorter than normal tooth roots. This predisposes to dental decay.
How does Klinefelter syndrome affect you socially?
Individuals with Klinefelter syndrome are more frequently shy. They tend to have low self-esteem, are impulsive, and suffer from emotional immaturity. Many suffer from attention-deficit/hyperactivity disorder. Some suffer from delayed speech development and fall on the autism spectrum scale. They have features of both males and females to varying degrees leading to identity issues. They are infertile. All of these characteristics increase the risk of depression and anxiety.
This article discusses the impact of living with Klinefelter syndrome.
How is Klinefelter syndrome treated?
Klinefelter syndrome frequently is not diagnosed until adulthood when a male finds it difficult fathering children and then undergoes genetic testing. It is treated with testosterone replacement therapy which is best started when a boy would normally go through puberty. This highlights the importance of having a high index of suspicion at an early age based on clinical features that one may have Klinefelter syndrome.
Klinefelter syndrome is typically diagnosed in one of the following ways:
- Prenatal screening.
- Testing after a healthcare provider notices abnormal growth during childhood, puberty, or throughout the teen years.
- Testing for fertility issues and/or low testosterone in adulthood.
What are the signs of symptoms of Klinefelter syndrome?
Signs and symptoms of Klinefelter syndrome vary by the age of the male.
Signs and symptoms may include:
Infants
- Weak muscles
- Delayed motor development such as sitting, crawling, and walking
- Delay in speaking
- Undescended testicles at birth
Boys and teenagers
Signs and symptoms may include:
- Taller than average stature
- Longer legs, shorter torso, and broader hips compared with other boys
- Absent, delayed, or incomplete puberty
- Less muscle and less facial and body hair compared with other teens after puberty
- Small and firm testicles
- Small penis
- Enlarged breast tissue (gynecomastia)
- Weak bones (due to low testosterone levels)
- Low energy levels
- Tendency to be shy and sensitive
- Difficulty expressing thoughts and feelings or socializing
- Problems with reading, writing, spelling, or math
Men
Signs and symptoms may include:
- Low sperm count or no sperm
- Small testicles and penis
- Low sex drive
- Taller than average height
- Weak bones
- Decreased facial and body hair
- Less muscle compared with other men
- Enlarged breast tissue or gynecomastia
- Increased belly fat
What is the Life Expectancy in Klinefelter syndrome?
Some studies indicate that the life expectancy of an individual with Klinefelter syndrome is shortened by two years.
Are Eye Disorders Associated with Klinefelter Syndrome?
There are isolated reports of eye disorders occurring in individuals with Klinefelter syndrome. In some cases, Klinefelter syndrome patients show decreased peripheral corneal thickness and volume. Some show a smaller foveal avascular zone and decreased retinal thickness. On visual field testing, some require brighter stimuli. All of this suggests that Klinefelter individuals should have an ocular exam.
