Chemicals You Were Exposed to Before Birth May Be Scrambling Your Future Children’s DNA
Ben Sullivan
During meiosis, the process by which sperm are made, chromosomes must sort themselves with extraordinary precision. Each mature sperm cell is supposed to carry exactly 23 chromosomes: one sex chromosome, either X or Y, and 22 others. When the sorting goes wrong, a sperm ends up with an extra chromosome, sometimes two sex chromosomes instead of one, sometimes none at all. Most of the time this matters little; aneuploid sperm rarely fertilise successfully. But when they do, the consequences can...