Klinefelter Syndrome

Klinefelter syndrome is a congenital condition, which means it’s present from the time of birth. There are certain tests that can be done during the mother’s pregnancy that can diagnose it before birth, however more often it’s diagnosed later in life.

Causes of Klinefelter Syndrome #

• Typically, a person’s genetic code is made up of either two X chromosomes (genetic female) or one X and one Y chromosome (genetic male).

• At conception, the mother has one chromosome in an egg and the father has one in the sperm.

• The egg holds an X.

• The sperm could have either an X or a Y chromosome.

• In a typical situation, if an X sperm meets an egg holding an X, the resulting baby will be a female (46, XX).

• If the sperm holds a Y chromosome when it meets the egg, the resulting baby will be a male (46, XY).

• Klinefelter syndrome happens when there is an extra X chromosome in the genetic code. This change happens before birth and can happen in a few different ways.

These ways include:

• A sperm cell carries an extra X chromosome.

• An egg cell holds an extra X chromosome.

• Cells divide incorrectly early in the development process of a fetus (called mosaic Klinefelter syndrome).

Symptoms of Klinefelter Syndrome #

• Being born with a smaller penis, and/or undescended testicle(s).

• Having abnormal body proportions. (This can include being too tall, having long legs and a short trunk and the shoulders being equal to hips in size rather than wider, which is more typical in a male.)

• Having flat feet or an unusual fusion of certain bones in the forearms.

• Having difficulty with gross motor function (coordination).

• Having testicular failure (not making enough testosterone or sperm).

• Experiencing increased breast tissue (gynecomastia) in teen or adult years.

• Having an increased risk for blood clots.

• Having weaker bones or more fractures (called either osteopenia or osteoporosis as an adult).

Diagnosis of Klinefelter Syndrome #

• To diagnose Klinefelter syndrome, your doctor will start with a physical exam and questions about your symptoms and general health.

• They’ll probably 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 blood test looks at your chromosomes.

Hormone tests #

These check hormone levels in your blood or urine.

Treatment of Klinefelter Syndrome #

• It’s never too late to treat Klinefelter, but the earlier you start, the better.

• One common treatment is testosterone replacement therapy.

• It can start at puberty and can spur 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 include:

• Counseling and support for mental health issues

• Fertility treatment (in some cases, using your own sperm to father a child)

• Occupational therapy 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