DELETIONS

Small deletions are less likely to be fatal; large deletions are usually fatal - but always, there is variation based on what genes are lost. Some medium-sized deletions lead to recognizable human disorders.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.[1] A deletion of part of the short arm of chromosome 5 results in a syndrome called Cri du chat,[1] also known as "cry of the cat" syndrome. It is found in approximately 1 in 50,000 live births. The surviving infants have a distinctive cry, severe mental retardation, and shortened life span.