What´s Klinefelter Syndrome?

Klinefelter syndrome is a chromosomal abnormality that leads to alterations in the male phenotype. These alterations appear in both the physical and cognitive development. Males affected by this disorder carry an extra X chromosome, which results in androgen deficiency, hypogonadism, and infertility. Instead of being inherited, Klinefelter syndrome is due to spontaneous events during the formation of the parental germ cells. These events lead to an extra X chromosome in the cells of the offspring.
Klinefelter syndrome is the most common sex chromosome disorder. This disorder affects nearly 1 in 500 males, and is thought to be underdiagnosed due the lack of severity in symptoms.