Klinefelter Syndrome

Klinefelter Syndrome is a chromosomal disorder. It is not inherited, rather it is a random genetic mutation, which causes males to have an extra X chromosome. It is relatively rare, affecting around 1 in every 660 male newborn infants.

Klinefelter can affect physical, intellectual, emotional and social development. For example, babies may be slower to reach physical developmental milestones, such as crawling and walking. As the condition causes hypogonadism - insufficient testosterone production - it can also delay puberty, or puberty may remain incomplete. This is linked to possible lower sex drive and infertility. It might also mean that muscles and bones are weaker. It is common for individuals with Klinefelter to experience mild learning disabilities such as as dyslexia. In early childhood, individuals with Klinefelter may be shy or lack confidence. Men with Klinefelter are also at a slightly increased risk of conditions such as anxiety and depression, type 2 diabetes, osteoporosis and cardiovascular disease.

Treatment for Klinefelter may include hormone replacement therapy (testosterone), as well as physical and occupational therapy. Psychological therapies and educational support might also be of benefit. Around 95 to 99% of men with Klinefelter are infertile, so require fertility interventions to have a family, such as IVF using donor sperm.

There is an excellent set of videos on YouTube called XXY: Men Talking About Having Klinefelter Syndrome which I thoroughly recommend.