The chromosomal condition called Klinefelter Syndrome

The chromosomal condition called Klinefelter Syndrome

Klinefelter syndrome (KS) is probably a condition you may never have heard of but yet is one of the most common chromosomal disorders seen in all newborn baby boys.  Klinefelter syndrome is the result of one extra X chromosome (written as XXY) in baby boys.  This syndrome is estimated to occur in about 1 out of every 500-1,000 newborn males.  It is not known what causes or increases the risk of KS but what is known is that the error producing the extra chromosome happens at random and is not hereditary.  The only suggested increased risk is that it occurs slightly higher in women who have pregnancies after age 35.

Normally, humans have 46 chromosomes containing all of a person’s genes and DNA.  The sex hormones which are two of the 46 chromosomes, determine a person’s gender at conception.  Baby girls have two X chromosomes (written as XX) while baby boys have an X and a Y chromosome (written as XY).  These important hormones guide the development of females and males toward the sexual characteristics of their gender and to become fertile during puberty.

Symptoms of Klinefelter syndrome

Klinefelter syndrome is a type of condition that it is possible a man may have it and not even know it.  That is because males with the XXY chromosome do not appear that much different from other males or their symptoms are very mild or nonexistent.  During the first few years of life, males with KS may not show any symptoms other than possibly having slightly weaker muscles in which they may have slight developmental delays such as sitting up, crawling, or walking a little later than average. 

But other males with KS can have more noticeable symptoms which often depend on several factors including how much testosterone his body makes.  If a male has low testosterone levels, then physical symptoms are more prominent. 

Some physical symptoms males with KS may have include the following:

·      Slower in developing motor skills, coordination, speed, and muscle strength

·      Fatter around the belly

·      Clumsier

·      Smaller testes and penis

·      Breast growth (affects about one-third of teens)

·      Less facial and body hair

·      Reduced muscle tone

·      Narrower shoulders and wider hips

·      Decreased sexual interest

·      Weaker bones, higher risk for bone fractures

·      Lower energy

·      Low testosterone levels

Another symptom that affects nearly all men with KS is reduced sperm production or infertility.  Almost all men with KS will be unable to father a child without the help of a fertility specialist.

Some social/behavioral symptoms males with KS have can include a quieter, less assertive personality, more anxious, less physically active, eager to please, and more likely to follow directions. 

How is it diagnosed?

To diagnosis KS a chromosomal analysis involving taking a blood sample is necessary to confirm it. The analysis will separate white blood cells from the sample, mix them with tissue culture medium, incubated, and then checked for chromosomal abnormalities such as an extra X chromosome.

Can Klinefelter syndrome be treated or cured?

There is no cure for KS as it is not possible to remove the extra X chromosome from cells.  However, the symptoms can be treated successfully helping to minimize the impact of the condition. 

About half of all males with KS have low testosterone levels which can be treated by taking supplemental testosterone.  It is necessary for males to work closely with an endocrinologist, a doctor who specializes in hormones and will closely follow a man’s use of testosterone therapy. 

Testosterone therapy can help a male with KS by improving muscle mass, deepening the voice, promoting growth of facial and body hair, helping reproductive organs to develop, building and maintain bone strength, producing a more masculine appearance, and increasing focus and attention. 

There are several ways testosterone can be given:

·      Injections or shots, given every 2 to 3 weeks

·      Pills

·      Transdermal or applied directly to the skin by either wearing a testosterone patch or rubbing testosterone gel onto the skin

Longterm outlook for males with Klinefelter syndrome

The good news with KS is that the majority of men with this condition can expect to lead a productive, full life with a normal lifespan.  If they have low testosterone and are being treated for it, they can lead similar lives as men without KS by having successful and meaningful careers and professions along with strong relationships with family and friends.