1. Klinefelter’s Syndrome
AP Biology 2
3rd period
Michelle Xu &
Alice Thai

2. What is Klinefelter’s Syndrome?
Klinefelter's syndrome is a genetic disorder that only affects males.
It occurs when a boy is born with one or more extra X chromosomes, which causes a boy to produce less testosterone than a normal boy. .
Due to having an extra X chromosome, the male may possibly have some physical traits unusual for males.

3. What is Klinefelter’s Syndrome?
Instead of an XY sex chromosome pattern that most males have, these males have an XXY pattern.
Some people with Kleinfelter’s consider themselves to be transgender, intersexed, or transsexual, due to having a more feminine appearance and/or feminine emotions.

4. Other Names for Klinefelter’s:
47, XXY
XXY Syndrome
XXY Trisomy
Or 3+X Chromosomes with Y
Frequency of Klinefelter’s:
Approximately 1 in 500 to 1,000.

5. How do you get Klinefelter’s Syndrome?
An extra X chromosome most often occurs when the genetic material in the eggs or the sperm splits unevenly.
It’s a random event during the formation of reproductive cells
An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes.
It’s diagnosed in adulthood by using a karyotype.

6. Symptoms of Klinefelter’s Syndrome
Physical Symptoms:
Long legs
Wide hips
Enlarged breasts
Sparse body hair
Small testicles
Less muscular
Weaker bones

7. Symptoms of Klinefelter’s Syndrome
Language Symptoms:
Learn to talk late
Trouble expressing thoughts and needs
Problems reading
Trouble processing what they hear
Other Symptoms:
Normal sex lives, but cannot father children
Produce much less testosterone

8. Treatment of Klinefelter’s Syndrome
Males with Klinefelter’s Syndrome can be given testosterone therapy.
If given around the age of puberty, it can help a boy have normal body development.
A infertility specialist may be able to help a male with Klinefelter’s syndrome to get a woman pregnant.

9. History of Klinefelter’s Syndrome
In 1942, Klinefelter’s was discovered by Dr. Harry Klinefelter, along with other doctors at General Hospital in Boston.
Doctors reported a group of males with “enlarged breasts, sparse facial and body hair, small testes, and inability to produce sperm.”
By the late 1950’s, researches discovered that these men had an extra sex chromosome thus having the pattern XXY.

10. Lifestyle with Klinefelter’s Syndrome
As a Baby, Child, and Teen:
May sit up, crawl, and walk later than other infants.
Tend to be taller and have less muscle control than other boys.
May have language problems
Tend to be quiet and undemanding.
Entering puberty, these males don’t make as much testosterone.

11. Lifestyle with Klinefelter’s Syndrome
As an Adult:
Look similar to normal males, but are often taller.
Likely to have health problems such as breast cancer, vein diseases, tooth decay, and autoimmune disorders.
Cannot father children due to infertility.
May have a harder time doing work that involves reading and writing.
Normal social life with friends and family.

12. Caroline Cossey (XXXY)
Cossey was raised as a boy, but changed lifestyle to live as a girl.
She became a famous model.
She underwent sex-reassignment surgery.
Cossey was a James Bond girl in the movie “For Your Eyes Only.”

13. Lili Elbe Elbe allegedly had Klinefelter’s.
She was one of the first identifiable recipients of male to female sex reassignment surgery.
Elbe was a fashion model.
She was transsexual and underwent experimental surgeries, her first surgery was orchiectomy (removal of testicles).
Elbe was written about in David Ebershoff’s best seller, The Danish Girl.

14. Works Cited