What is Klinefelter's Syndrome?
Klinefelter's syndrome is a genetic condition whereby an additional X chromosome is found. This means that it is something you are born with which happens very early on in pregnancy, just after conception has taken place.
What is a chromosome?
Chromosomes are tiny microscopic structures found within every cell in every tissue of our body. Usually there are 23 pairs of chromosomes in each cell, making 46 altogether. Each parent provides one set of 23 chromosomes.
Within the chromosomes there are around 30,000 genes which determine characteristics such as hair and eye colour.
One chromosome from each parent will determine if a person is male or female.
These two special chromosomes are the X and the Y.
OK you still with me? This next bit can be a little confusing but I will keep things as simple as I can.
The Mother will always provide the X chromosome and the Father may provide either an X or Y chromosome.
A child that receives one X chromosome from each parent will be female giving them a genotype of 46XX.
If the Father provided a Y chromosome then the genotype would be 46XY and the child would be male
Boys with Klinefelter's syndrome have an extra X chromosome making their genotype 47XXY. The additional X chromosome can come from either parent.
I set out some diagrams in a word document to help explain this point. Unfortunately much as I have tried I can not publish them onto here!?