LONDON, ENGLAND—According to a Live Science report, Kyriaki Anastasiadou of the Francis Crick Institute and her colleagues developed a computational method that allowed them to identify six individuals with sex chromosomal conditions in the Thousand Ancient British Genomes database. The first person, who was between the ages of 18 and 22 at the time of death some 2,500 years ago, had mosaic Turner syndrome, in which some of the body’s cells had just one X chromosome, while others had two. Turner syndrome can lead to shorter-than-average height, cardiac problems, and small or missing ovaries. Three of the individuals likely had Klinefelter syndrome, in which a person carries XXY sex chromosomes. One of them lived in the Iron Age, between 750 B.C. and A.D. 43; one lived in the medieval period, between A.D. 1050 and 1290; and the third lived in the nineteenth century. Klinefelter syndrome can cause stunted growth of the testicles, lower testosterone levels, lower muscle mass, less body hair, and larger breast tissue than individuals with typical XY chromosomes. Another person with XYY chromosomes may have been taller than average. Finally, an infant who lived during the Iron Age was found to have Down syndrome, a condition caused by extra genetic material from chromosome 21. Read the original scholarly article about this research in Communications Biology. For more on ancient DNA, go to "Worlds Within Us."