Deletion



Deletion is a form of the chromosome structural abnormality.


 * It is characterized by the loss of a part of the chromosome.
 * Two breaks have to occur for deletion of the interstitial segment. For deletion of the terminal segment (telomere) one break is enough.
 * The segments which were deleted from the chromosome are not able to "live" on their own. It is the reason why we lose the genes which were coded by these part of the chromosome.

Ring Chromosome



 * The special case of deletion.
 * It is a situation when a chromosome loses both of its ends. The long and the small arms then connect together and the chromosome becomes ring-shaped.

Related articles

 * Chromosome abnormalities
 * Karyotype