In an individual heterozygous for a paracentric inversion during crossing over, a dicentric bridge can form.
How a dicentric bridge produced?
A paracentric inversion involves the inversion of a chromosome segment that does not include the centromere. During meiosis, homologous chromosomes with different inversion orientations may align improperly. Crossing over between inverted and non-inverted chromatids creates an abnormal structure with two centromeres, forming a dicentric bridge.
So, When the cell attempts to segregate during anaphase, the dicentric bridge may lead to chromosome breakage or aneuploidy. This aberration can result in genetic disorders due to the unequal distribution of genetic material between daughter cells.