Most often, boys and men with Klinefelter syndrome have the usual X and Y chromosomes, plus one extra X chromosome, for a total of 47 chromosomes (47,XXY). Boys and men with Klinefelter syndrome have an extra copy of multiple genes on the X chromosome.
How many chromosomes are in Klinefelter syndrome?
Klinefelter Syndrome (47, XXY) is a chromosomal variation in males in which one extra X chromosome is present, resulting in a 47,XXY karyotype. The extra X chromosome typically affects physical, neurodevelopmental, behavioral, and neurocognitive functioning.
What chromosome does Klinefelter syndrome affect?
Klinefelter syndrome (sometimes called Klinefelter’s, KS or XXY) is where boys and men are born with an extra X chromosome.
Can a girl have Klinefelter’s syndrome?
Klinefelter syndrome affects males only; females cannot have it. Klinefelter syndrome results from a genetic abnormality in which males have an extra copy of the X chromosome. Instead of the usual XY chromosomes, males with Klinefelter syndrome have an XXY pattern.
What is a person with XXY chromosomes?
Boys who have Klinefelter syndrome are born with it. It’s also called XXY because they have an extra X chromosome in most or all of their cells. Usually, a person has 46 chromosomes in each cell, divided into 23 pairs, which includes two sex chromosomes.
CAN XXY have babies?
It is possible that an XXY male could get a woman pregnant naturally. Although sperm are found in more than 50% of men with KS3, low sperm production could make conception very difficult.
What is the survival rate of Klinefelter syndrome?
We found that Klinefelter syndrome was associated with a significant increase in mortality risk of 40% (hazard ratio, 1.40; 95% confidence interval, 1.13-1.74), corresponding to a significantly reduced median survival of 2.1 yr.
What does a person with Klinefelter syndrome look like?
Longer legs, shorter torso and broader hips compared with other boys. Absent, delayed or incomplete puberty. After puberty, less muscle and less facial and body hair compared with other teens. Small, firm testicles.
Who is most likely to get Klinefelter syndrome?
Klinefelter syndrome results when a boy is born with at least 1 extra X chromosome. This is written as XXY. Klinefelter syndrome occurs in about 1 out of 500 to 1,000 baby boys. Women who get pregnant after age 35 are slightly more likely to have a boy with this syndrome than younger women.
How does Klinefelter syndrome affect a person’s life?
But the condition can bring challenges later in life. For example, guys with Klinefelter syndrome may be more likely to get some types of cancer and other diseases, like type 2 diabetes and osteoporosis, a condition where the bones become weaker later in life.
Can you be a girl with a XY chromosome?
The X and Y chromosomes are called “sex chromosomes” because they contribute to how a person’s sex develops. Most males have XY chromosomes and most women have XX chromosomes. But there are girls and women who have XY chromosomes. This can happen, for example, when a girl has androgen insensitivity syndrome.
Are XXY males infertile?
Between 95% and 99% of XXY men are infertile because they do not produce enough sperm to fertilize an egg naturally. But, sperm are found in more than 50% of men with KS.