On Aug. 29, 2022, a group of international researchers, coordinated by Dr Jo�o Teixeira at The Australian National University, announced they had uncovered evidence of a super rare genetic condition that gives men an extra X chromosome, reporting the oldest clinical case of Klinefelter Syndrome to date. The evidence comes from a 1,000-year-old skeleton from Portugal.

Klinefelter Syndrome is a rare genetic condition where individuals are born with an extra copy of the X chromosome, occurring in approximately one in 1,000 genetic-male births.