Genetics Home > Klinefelter Syndrome Symptoms
Common symptoms of Klinefelter syndrome include breast development, smaller testes, and sparse facial and body hair. In addition, boys with Klinefelter syndrome may have learning disabilities and difficulty with speech and language development. The signs and symptoms of this syndrome vary, and some men who have the extra chromosome may not have symptoms at all.
The XXY chromosome arrangement appears to be one of the most common genetic abnormalities known, occurring as frequently as 1 in 500 to 1 in 1,000 male births.
But while many men have an extra sex chromosome, not a lot actually have symptoms of Klinefelter syndrome. Many men live out their lives without even suspecting that they have an additional chromosome.
When an extra chromosome does cause Klinefelter syndrome symptoms, the symptoms can vary. Some men may have many symptoms; others only a few.
Common Klinefelter syndrome symptoms can include:
- Breast development (gynecomastia). Ten percent of males with Klinefelter syndrome will develop breasts large enough to embarrass them.
- Reduced facial and body hair.
- Small testes.
In addition to having these symptoms, males with Klinefelter syndrome are more likely than other males to be overweight, and tend to be taller than their fathers and brothers.
Boys with Klinefelter syndrome symptoms may have learning disabilities and difficulty with speech and language development. They tend to be quiet, sensitive, and unassertive, but personality characteristics vary among males with this condition.