This syndrome is characterized by a chromosomal abnormality in males in which there is an extra X chromosome. Normally, when we study the chromosomes in a man, we find 46, XY, but in these cases affected by Klinefelter syndrome, we find 47, XXY.
The physical consequences can be multiple, and if analytical studies are carried out, hormonal failure and sterility due to alteration in sperm production at the level of the testicles can be found.
Each case must be assessed individually. In some cases, sperm can be extracted directly from the testicles through a testicular biopsy. If this is the case, then an IVF treatment with microinjection of one spermatozoon into each egg (ICSI) must be performed, with the possibility of a genetic study of the embryos to check chromosomal normality.