An Introduction

Klinefelter’s Syndrome (KS) isn’t rare – but it is rarely diagnosed.

It is  a common congenital condition which is found in around 1 in 600 live male births and is caused by the presence of one or more additional sex chromosomes.

Although it is generally associated with males, there appear to be a number who identify as both male and female, as neither male nor female or as female.

For more information see KS or XXY? and gender issues.

KS is diagnosed by a genetic blood test which identifies the karyotype – 47,XXY. There may be additional X chromosomes and there is a mosaic form 46,XY/47,XXY.

Early diagnosis and appropriate support can make a huge difference to those affected.

The condition is most commonly diagnosed as a result of fertility investigations as KS adults are almost always unable to father children by normal means. However, some may have some residual fertility.

The usual treatment is testosterone replacement therapy although this may not suit all.

Next… The Klinefelter’s Syndrome Association (KSA)