"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).

Prenatal checks revealed that the unborn child has XYY syndrome, a genetic condition which has been wrongly linked to criminal behaviour. On July 14, six-month pregnant Jiujiu from Sichuan ...