Klinefelter SyndromeBy:ASLAM MATANIAGROUP-3FACULTY OF MEDICINE TSMU

What is Klinefelter’s Syndrome?

Klinefelters syndrome is a genetic condition caused when someone has two X chromosomes and one Y chromosome

Because people with an XXY chromosome arrangement have a Y chromosome, they are considered genetic males

Most XXY individuals develop as males, often not knowing they have an extra chromosome.

Physical characteristics of disorder may appear around the time of puberty

Some people with Kleinfelter’s consider themselves to be transgender, intersexed, or transsexual, due to having a more feminine appearance and/or feminine emotions.

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.

Causes of Klinefelter Syndrome The main error in development that leads

to Klinefelter syndrome is a nondisjunction. Nondisjunction is when the chromosomes

do not separate correctly during cell division

In the case of Klinefelter syndrome, the sex chromosomes fail to separate, resulting in an extra X chromosome that is associated with this disease.

There are several reasons why the chromosomes would fail to separate during meiosis or mitosis.

If the centromere sequence is deleted from a chromsome, the kinetochore proteins will not be able to attach.

The lack of kinetochore proteins will not allow the microtubules to attach to the chromosomes, which can result in the chromosome being randomly distributed in the resulting cells.

There are spindle apparatus checkpoints during the cell cycle.

If the chromosomes do not align properly along the metaphase plate, the cell will perform apoptosis.

If this checkpoint is not present, the cell will continue through division with the incorrect chromosome alignment.

This can result in aneuploidy.

What are the symptoms ? The XXY chromosome arrangement

affects primarily sexual development. Typically, testes don't fully develop, and

the levels of the hormone testosterone (important for male sexual development) are lower than average.

As adults, nearly all XXY males are unable to make sperm and so cannot have biological children.

Many men discover their condition only after they seek medical help for infertility.

Physical Symptoms: Long legs Wide hips Enlarged breasts Sparse body hair Small testicles Less muscular Weaker bones

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

diagnosis If a doctor suspects that an individual

may be XXY (based on physical characteristics, most commonly infertility), the diagnosis can be made using a karyotype

A karyotype is an analysis of a patient's chromosomes taken from a blood sample.

It is diagnosed during pregnancy by taking amniotic fluid

Treatment 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.