Translocation

Translocation is the movement of a piece or a whole chromosome onto another chromosome. The acrocentric nature of Chr 21 and it’s small size makes it prone to an event called Robertsonian Translocation whereby two acrocentric chromosomes fuse.

Down’s Syndrome from a 14:21 translocation.

A spectral karyogram of a brain cancer (glioblastoma) illustrating multiple translocation problems and chromosome instability. Credit: Thomas Reid, NCI (CC-BY-NC)

Abnormalities in mitosis also occur and can result in diseases from translocations.