Klinefelter syndrome is a genetic condition ... chromosome in the egg or the sperm may result in conditions such as Turner syndrome, a "monosomy" which has the arrangement 45, XO.) ...

"You either have XX or XY chromosomes," Rep. Nancy Mace, R-S.C., wrote Feb. 20 on X. "Those are the options." Most commonly, a person is born with two X chromosomes (female) or an X and a Y (male).

Klinefelter syndrome is the most common sex-chromosome disorder; it affects approximately one in every 660 men. This syndrome is characterized by the presence of one or more extra X chromosomes ...

Like Klinefelter Syndrome, Turner Syndrome is marked by an abnormal karyotype, 45,XO. While Turner women have female external genitals, the individuals lack properly formed ovaries. Without ...

Testosterone treatment significantly reduces mortality among men with Klinefelter syndrome. Researcher calls for changes in guidelines to ensure more patients receive the necessary treatment.