What is Klinefelter syndrome?
What is Klinefelter syndrome?
Klinefelter syndrome is a chromosomal condition that affects male sexual development. Males with this condition typically have small testes that do not produce enough testosterone, which is the hormone that directs male sexual development before birth and during puberty. A shortage of testosterone during puberty can lead to breast enlargement (gynecomastia), reduced facial and body hair, and an inability to father children (infertility). Older children and adults with Klinefelter syndrome tend to be taller than other males their age. Compared with other men, adult males with Klinefelter syndrome have an increased risk of developing breast cancer and a chronic inflammatory disease called systemic lupus erythematosus. Their chance of developing these disorders is similar to that of normal adult females.
Boys with Klinefelter syndrome 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.
Most males with Klinefelter syndrome have one extra copy of the X chromosome in each cell. Variants of Klinefelter syndrome involve more than one extra X chromosome or extra copies of both the X and Y chromosomes in each cell. These conditions tend to have more severe signs and symptoms than classic Klinefelter syndrome. In addition to affecting male sexual development, variants of Klinefelter syndrome are associated with intellectual disability, distinctive facial features, skeletal abnormalities, poor coordination, and severe problems with speech.
How common is Klinefelter syndrome?
Klinefelter syndrome affects 1 in 500 to 1,000 males. Most variants of Klinefelter syndrome are much rarer, occurring in 1 in 50,000 or fewer male births. Klinefelter syndrome does not occur in females.
What are the genetic changes related to Klinefelter syndrome?
Klinefelter syndrome is a condition related to the X
Klinefelter syndrome is a chromosomal condition that affects male sexual development. Males with this condition typically have small testes that do not produce enough testosterone, which is the hormone that directs male sexual development before birth and during puberty. A shortage of testosterone during puberty can lead to breast enlargement (gynecomastia), reduced facial and body hair, and an inability to father children (infertility). Older children and adults with Klinefelter syndrome tend to be taller than other males their age. Compared with other men, adult males with Klinefelter syndrome have an increased risk of developing breast cancer and a chronic inflammatory disease called systemic lupus erythematosus. Their chance of developing these disorders is similar to that of normal adult females.
Boys with Klinefelter syndrome 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.
Most males with Klinefelter syndrome have one extra copy of the X chromosome in each cell. Variants of Klinefelter syndrome involve more than one extra X chromosome or extra copies of both the X and Y chromosomes in each cell. These conditions tend to have more severe signs and symptoms than classic Klinefelter syndrome. In addition to affecting male sexual development, variants of Klinefelter syndrome are associated with intellectual disability, distinctive facial features, skeletal abnormalities, poor coordination, and severe problems with speech.
How common is Klinefelter syndrome?
Klinefelter syndrome affects 1 in 500 to 1,000 males. Most variants of Klinefelter syndrome are much rarer, occurring in 1 in 50,000 or fewer male births. Klinefelter syndrome does not occur in females.
What are the genetic changes related to Klinefelter syndrome?
Klinefelter syndrome is a condition related to the X