Klinefelter syndrome

This is an unusual (affects about 1 in 600 men) condition that is caused by a genetic issue where all cells in the body have an extra chromosome.  This 47,XXY chromosome complement can result in altered testicular function with low testosterone and very low sperm production.  Increasingly, Klinefelter diagnosis may be made before birth or in adolescents, so consideration of steps that can be taken with hormonal support or fertility preservation are important for adolescents.  Some of our research has shown that early surgical intervention is not necessary for most young men with Klinefelters, but careful hormonal monitoring may be helpful ( https://pubmed.ncbi.nlm.nih.gov/31587581/  Another article on this topic was published in 2023 – in press  ).  An 18 minute video overview of this condition is available here: https://youtu.be/VGmJREpZtBc

We have treated hundreds of men with this condition, and we were the first group to allow successful fertility treatment for men with Klinefelter syndrome ( https://pubmed.ncbi.nlm.nih.gov/9475766/).  We continue to develop new understanding of how to optimize hormone levels and provide new fertility treatment approaches and have allowed nearly 70% of all men with Klinefelters to have the opportunity to be fathers of their own genetic children.