Isochromosomes

**Definition:** Metacentric chromosomes produced during MEIOSIS or MITOSIS when the CENTROMERE splits transversely instead of longitudinally. The chromosomes produced by this abnormal division are one chromosome having the two long arms of the original chromosome, but no short arms, and the other chromosome consisting of the two short arms and no long arms. Each of these isochromosomes constitutes a simultaneous duplication and deletion.

**Tree numbers:** - A11.284.187.570 - C23.550.210.430 - G05.360.162.570 - G05.365.590.175.430