Klinefelter syndrome overview
Klinefelter syndrome (KS), also known as 47,XXY or XXY, is the set of symptoms that result from two or more X chromosomes in males. The primary features are infertility and small testicles. Often, symptoms may be subtle and many people do not realize they are affected.
Klinefelter syndrome usually occurs randomly. An older mother may have a slightly increased risk of a child with KS. The condition is not typically inherited from one’s parents.
The underlying mechanisms involves at least one extra X chromosome in addition to a Y-chromosome such that the total chromosome number is 47 or more rather than the usual 46. KS is diagnosed by the genetic test known as a karyotype. While no cure is known, a number of treatments may help.
Causes of Klinefelter syndrome
- An extra X chromosome in every cell, which is the most common
- An extra X chromosome in only some cells, called mosaic Klinefelter, where you don’t get as many symptoms
- More than one extra X chromosome, which is very rare and more severe
Symptoms Klinefelter syndrome
- More quiet than usual
- Slower to learn to sit up, crawl, and talk
- Weaker muscles
Children: Boys may have low energy levels or any of the following:
- A hard time making friends and talking about feelings
- Problems learning to read, write, and do math
- Shyness and low confidence
- Infertility (can’t have children because they can’t make enough sperm)
- Low sex drive
- Low testosterone levels
- Problems getting or keeping an erection
Other Conditions caused by Klinefelter syndrome
Many problems caused by Klinefelter are because of lower testosterone levels. You may have a slightly higher chance of:
- Autoimmune problems, such as lupus and rheumatoid arthritis, where your immune system attacks healthy parts of your body
- Breast cancer and cancers that affect blood, bone marrow, and lymph nodes
- Conditions with your hormone glands, such as diabetes
- Heart disease and problems with blood vessels
- Lung disease
- Mental health problems, such as anxiety and depression
- Weak bones, called osteoporosis
Diagnosis and Tests of Klinefelter syndrome
Your doctor will start with a physical exam and questions about your symptoms and general health. He’ll likely examine your chest, penis, and testicles and do a few simple tests, such as checking your reflexes.
Your doctor may then run two main tests
Chromosome analysis: Also called karyotype analysis, this is a blood test that looks at your chromosomes.
Hormone tests: These check hormone levels in your blood or urine.
It’s never too late to get treatment, but the earlier you start, the better.
One common treatment is testosterone replacement therapy. It starts at puberty and can spur on typical body changes, such as facial hair and a deeper voice. It can also help with penis size and stronger muscles and bones, but it won’t affect testicle size or fertility.
Testosterone replacement therapy throughout your life can help prevent some of the long-term problems that come with Klinefelter.
Other treatments may include:
- Counseling and support for mental health issues
- Fertility treatment (in some cases, using your own sperm to father a child)
- Occupational and physical therapy to help with coordination and build muscles
- Plastic surgery to reduce breast size
- Speech therapy for children
- Support in school to help with social skills and learning delays
If your child has Klinefelter, you can suggest that he:
- Play sports and other physical activities to build muscles
- Take part in group activities to learn social skill