Klinefelter syndrome, also known as XXY syndrome, is a condition in boys and men that’s caused by an extra X chromosome. It can affect physical and mental development.

The prevalence of both SLE and Sjögren disease was 0.5% in patients with Klinefelter syndrome, while the prevalences of SLE and Sjögren disease were 1.3% and 0.8%, respectively, in patients with ...

Klinefelter syndrome is the most commonly occurring sex-chromosome disorder, and it often goes undiagnosed. In this article the authors discuss the diagnosis and the clinical features and ...

New Treatment for Klinefelter's Syndrome Infertility Additionally, these cells could not move to the right location in the testes, which is necessary for them to grow into mature, sperm-producing ...

Klinefelter syndrome is a genetic condition that occurs when a male is born with an extra copy of the X chromosome, affecting an estimated 1 in 1,000 individuals. Symptoms of Klinefelter syndrome may ...

Characteristics of Klinefelter syndrome in babies. Symptoms and features may include: Weak muscles Slow motor development — takes longer than average to sit, crawl, and walk .