Klinefelter Syndrome

Estrada, Civer Charm

Floresca, JasonGabayeron, LorenGranadillos, RyanHao, Carl jason

Jacob, MelissaJalbuna, ElizabethJavellana, Bea JoiJayme, Paul Ivin

Lee, Edward

Group 5

It describes a group of symptoms found in some

men with an extra X chromosome. In 1942, Dr. Henry Klinefelter and some of his co-workers at Massachusetts General Hospital in Boston published a report about nine men with: enlarged breasts sparse facial and body hair small testes an inability to produce sperm

and it was this cluster of symptoms that became known as Klinefelter Syndrome.

Background

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.

Definition

Klinefelter syndrome is a condition related to

the X chromosome and Y chromosome (the

sex chromosomes).

People typically have two sex chromosomes in

each cell: females have two X chromosomes

(46,XX), and males have one X and one Y

chromosome (46,XY).

What are the genetic changes related to Klinefelter

syndrome?

Most often, Klinefelter syndrome results from

the presence of a single extra copy of the X

chromosome in each of a male's cells (47,XXY).

Extra copies of genes on the X chromosome

interfere with male sexual development,

preventing the testes from functioning normally

and reducing the levels of testosterone

48, XXYY Mild mental

retardation

Tall stature

Gynecomastia

Long, thin limbs

Small testes

48, XXXY Mild to moderate

mental retardation

Slow motor

development

Poor coordination

Immature behavior

Abnormal face

Klinefelter Variants

Hypertelorism

Clinodactyly

49, XXXYY

Moderate to severe

mental retardation

Passive but

occasionally

aggressive behavior

Temper tantrums

Tall stature

Gynecomastia

Hypogonadism

49, XXXXY Mild to moderate

mental retardation

Radioulnar synostosis

Hypergonadotropic

hypogonadism

Severely impaired

language

Behavioral problems

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.

Prevalence

90% have the XXY karyotype which is caused

by meiotic nondisjunction of the X chromosome during gametogenesis

10% have a mosaic karyotype caused by nondisjunction of the x chromosome during early mitosis of the zygote

Klinefelter's Syndrome

47,XXY

XXY Syndrome

XXY Trisomy

Other names:

The type and degree of symptoms displayed in

men with the XXY Condition depends on how

many XXY cells the man has, how much

testosterone his body is producing, and his

age when the condition was diagnosed.

Late physical development as a baby is one of

the earliest presentations of the condition.

Signs and Symptoms

As the child grows he may be taller than

his peers but have less muscle control and

coordination.

In puberty he may have less facial and

body hair and be broader in the hips than

other boys.

Enlarged breasts (gynecomastia), weaker

bones and less energy are experienced in

teens, and adult men with XXY are often

taller than their peers.

Patients may lack secondary sexual

characteristics because of a decrease in

androgen production. This results in sparse

facial, body, or sexual hair; a high-pitched

voice; and fat distribution as is observed in

females.

Infertility, azoospermia, or both may result

from atrophy of the seminiferous tubules. 

Most men with XXY are able to enjoy a normal

sex life, but 95 to 99 percent of them are

infertile. In fact, the condition is often not

even discovered until a man undergoes

genetic testing in order to determine the

cause of his sterility.

Children with XXY may also have

trouble learning to talk, using

language to express their

thoughts and needs, and

processing what they hear. These

problems generally resolve

themselves as the child ages, but

adult men may continue to have

trouble with tasks that involve

reading and writing.

Pronounced shyness, lack of self-confidence, and a

tendency to be more helpful and obedient than

other children are also possible early symptoms of

XXY.

By adulthood, XXY males look similar to males

without the condition, although they are often taller.

They are also more likely than other men to have

certain health problems, such as autoimmune

disorders (SLE), breast cancer, vein diseases,

osteoporosis, and tooth decay.

Varicose veins occur in 20-40% of patients.

The prevalence of venous ulcers is 10-20

times higher than in healthy individuals,

and the risk of deep vein thrombosis and

pulmonary embolism is increased.

Patients may exhibit behavioral problems

and psychological distress. This may be

due to poor self-esteem and psychosocial

development or a decreased ability to deal

with stress.

A karyotype is used to confirm the

diagnosis. In this procedure, a small

blood sample is drawn.

White blood cells are then separated

from the sample, mixed with tissue

culture medium, incubated, and

checked for chromosomal

abnormalities, such as an extra X

chromosome.

Diagnostics

The genetic variation is irreversible, but its

symptoms can be altered or treated in a number of ways, including testosterone treatment and other therapies.

Inadequately treated hypogonadism in Klinefelter syndrome increases recognized psychosocial morbidity.

Support and acceptance is strongly recommended for the patient.

Treatment

Infertility is nearly universal

Physical findings are generally subtle

Behavioral characteristics are highly variable

On average adults have modestly reduced

intelligence verbal reasoning, language skills

and motor dexterity

Increased number of X chromosomes is

correlated with increase phenotypic severity

Prognosis

This condition is not inherited;

it usually occurs as a random

event during the formation of

reproductive cells (eggs and

sperm). An error in cell division

called nondisjunction results in

a reproductive cell with an

abnormal number of

chromosomes.

Can it be inherited?

For example, an egg or sperm cell may

gain one or more extra copies of the X

chromosome as a result of

nondisjunction. If one of these atypical

reproductive cells contributes to the

genetic makeup of a child, the child will

have one or more extra X chromosomes

in each of the body's cells.

Any questions?

Thank you for listening!