A gene deletion, or deletion mutation is a genetic mutation in which a part of a chromosome or a sequence of DNA is missing. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome (Lewis, 2005, p.226). Deletions can be caused by errors in chromosomal crossover during meiosis.

Deletion of a number of base pairs that is not evenly divisible by three will lead to a frameshift mutation, causing all of the codons occurring after the deletion to be read incorrectly during translation, producing a severely altered and potentially nonfunctional protein.

Deletions are responsible for an array of genetic disorders, including some cases of male infertility and two thirds of cases of Duchenne muscular dystrophy (Lewis, 2005, p.226). A deletion of part of the short arm of chromosome 5 results in Cri du chat (Lewis, 2005, p.256).

Reference

• Lewis R. 2005. Human Genetics: Concepts and Applications, 6th Ed. McGraw Hill, New York.

Deletion