Klinefelter Syndrome: The Missing X

Klinefelter syndrome is a genetic disorder that occurs in men when they are born with an additional X chromosome. This chromosome results in numerous symptoms that impact the male reproductive system as well as fertility. Here’s everything you need to know about the the syndrome itself and when it may help to see a fertility doctor.

In human development, the sex of the embryo is determined by the XY sex-determination system. This means that two sex chromosomes will determine the sex of a human being. Males will typically have an X and a Y chromosome, while females will have two Xs. The chromosomes hold all of the genetic code that your body needs.

However, in Klinefelter’s syndrome, males have an additional X chromosome due to a random genetic event. This means that they are XXY rather than just XY. An individual with Klinefelter is born with this genetic disorder, and nothing was done to cause it. Around 1 in every 500 to 800 males born suffers from Klinefelter’s.

While an additional chromosome may not seem like a big deal initially, chromosomes contain genetic material. Thus, any disruption to the body’s typical system can cause problems. For men with Klinefelter’s Syndrome, these problems vary, and cases don’t always look the same. Most individuals with this genetic disorder are diagnosed as adults. That said, here are just some of the signs and symptoms that you can look for:

• Slow motor development
• Speech delays
• Issues with male reproductive system at birth
• Weak muscles

• Longer legs, shorter torso, broader hips, taller than average
• Absent, delayed or incomplete puberty
• Small, firm testicles
• Small penis
• Enlarged breast tissue
• Weak bones
• Problems with reading, writing, spelling or math
• Shyness and sensitivity

• Low or no sperm count
• Low sex drive
• Small testicles and penis
• Taller than average height
• Weak bones
• Increased belly fat

Many men aren’t diagnosed with Klinefelter’s syndrome until they realize they’re unable to father a child due to low or no sperm count. About 3 percent of infertile males suffer from this genetic disorder. If you and your partner are experiencing difficulty becoming pregnant, reach out to a fertility doctor so that you can get the help you need.

With that, if you believe you or your son are experiencing the above signs and symptoms during infancy or boyhood, consult a trusted medical professional for treatment. Any concerns about delays in growth and development should check for Klinefelter’s along with other possible genetic disorders.