People who have one of several well-documented medical conditions do not have only XX or XY chromosomes, which typically correspond with female and male sexes, respectively. Those conditions include ...

Klinefelter syndrome is a genetic condition that affects only males. Here's what you should know about the causes, symptoms, and treatment options for the condition. Klinefelter syndrome is a genetic ...

The president’s executive order signaled an intention to narrowly define the sexes, but experts say he is oversimplifying the ...

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

The Department of Health and Human Services, under the leadership of Robert F. | The Department of Health and Human Services, ...

The scientist points out, for example, that some people we might think of as male have XYY or XXY sex chromosomes, which aren’t typical of either sex. The scientist also mentions that people ...

Genetics is the branch of science concerned with genes, heredity, and variation in living organisms. It seeks to understand the process of trait inheritance from parents to offspring, including ...