Klinefelter Syndrome (XXY ): People with this condition, first identified in 1942, have an extra X chromosome. People with this syndrome are typically assigned male at birth; the condition can result ...

In animals, including humans, recent studies have highlighted the influence of sex chromosomes on the aging process. Within a ...

"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).

A recent Trump executive order defines sex based on gamete size. But the order oversimplifies genetics, hormones and reproductive biology.

The NDP gene is found on the X chromosome — otherwise known as the female sex chromosome. (Human females typically have two X ...

In their effort to answer a decades-old biological question about how the hepatitis B virus (HBV) is able to establish ...