Karyotype Disorder Reading Packet

Read the information below, and answer the questions on the handout provided.

Klinefelter's Syndrome

Klinefelter's syndrome is found in approximately 1 of 700 men. This means that there are approximately 3600 boys and men with Klinefelter's syndrome in Denmark with 5 million inhabitants. Men usually have but one X and one Y chromosome. Men with Klinefelter's syndrome have more than one X chromosome, usually two X chromosomes.

At birth the testicles of Klinefelter boys are of normal size. When the testicles grow quickly in boys with normal chromosomes at the age of 11-12 years, the testicles of Klinefelter boys stay very small, as a rule only 2 cms from pole to pole. Usually only few sperm are developed in the testicles, and men with Klinefelter's syndrome are as a rule infertile. Boys with Klinefelter's syndrome should be treated with testosterone, usually at 11 or 12 years of age. Treatments could include Restandol tablets, which does not affect the liver, or with injections of other testosterone preparations.

Klinefelter boys more often than other boys have delayed motor function, speech, and maturation development, which does not make them patients demanding special treatment. If the speech development is delayed, it is important to get help from a speech-therapist for a period of time. Regarding the motor function development, the participation of parent/child in sports activities and group activities of any kind is of great value. The same is the case with regard to stimulating the delayed development in maturation. In this connection it must be mentioned, that it is also important to stimulate these boys to independence, and not in any way to overprotect them.

There will be less muscle development in puberty and late puberty, with increased tiredness and need for sleep. This can be counteracted, and usually eliminated, by relevant testosterone treatment from the age of 11- 12 years. For better muscle development and motor function it is of great importance to take part in different sports activities through childhood.

If Klinefelter boys grow up in a good, stable, and stimulating environment, the intelligence may be inside the normal area.

Turner’s Syndrome

Turner’s syndrome is a disorder caused by the loss of genetic material from one of the sex chromosomes.

Humans normally have a total of 46 chromosomes (which are tiny, DNA-containing elements) that are present in every cell of the body. DNA encodes genes, which specify all the proteins that make up the body and control its functions.

In humans, there are 23 matched pairs of chromosomes in every cell. Each cell contains 22 pairs of chromosomes called autosomes that are the same in males and females. The remaining pair of chromosomes, the X- and Y-chromosomes, are not shaped similarly, and thus are not matched in the same way as the autosomes.

The X- and Y-chromosomes are called sex chromosomes. They are responsible for the difference in development between males and females. A Y-chromosome contains genes responsible for testis development; and the presence of an X-chromosome paired with a Y-chromosome will determine male development. On the other hand, two X-chromosomes are required for normal ovarian development in females.

Women with Turner's Syndrome lack one or part of one of the so-called X chromosomes, i.e. sex-chromosomes, that carry genes for conditions relating to the development of ovaries, sex-hormone production, and physical development in general. This relationship leads to faulty development of the ovaries and sex-hormone production, and due to this these women usually cannot get pregnant. Menstruation usually also fails to come, and usually they do not have normal development of breasts and pubic hair. Estrogen treatment should be given from the age of about 12, starting with very small doses.

Is Turner’s Syndrome Hereditary?

While Turner syndrome is genetic in