Hypothetical model for the generation of iso-p and iso-q chromosomes during mitosis. When entering mitosis, one of the three copies of Chromosome 14 (p-arm in red, q-arm in blue) undergoes transversal division instead of the canonical longitudinal one, leading to the inheritance of the iso-p chromosome, shown in red, along with two copies of Chromosome 14 on one daughter cell and of the iso-q, shown in blue, and two copies of Chromosome 14 in the other.