Ancient DNA reveals first known case of sex-development disorder

The earliest known case of Turner syndrome has been found in the genome of an Iron-Age woman who lived in Britain roughly 2,500 years ago. Turner syndrome occurs in females and is characterised by having one complete copy of the X chromosome, instead of the usual two. The team also identified four ancient males with sex-chromosome disorders, including the earliest known person to have an extra Y chromosome, known as Jacob’s syndrome. The man lived around 1,100 years ago, during the Early Mediæval Period.