Definition: A paracentric 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. Paracentric inversions do not include a chromosome’s centromere. A paracentric 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 make it more likely for a person with a paracentric inversion to have a baby with health problems caused by extra or missing genetic information.