Definition: A pericentric inversion occurs when a portion of one chromosome, or a packet of genetic information, is flipped so that the order of genetic information changes. Each chromosome has a portion near the middle called a centromere. Pericentric inversions include a chromosome’s centromere. A pericentric inversion causes chromosomes to pair differently during the cell division that creates egg and sperm cells. These egg and sperm cells may have extra or missing genetic information. This can make it more likely for a person with a pericentric inversion to have a baby with health problems caused by extra or missing genetic information.