Effects
Small deletions are less likely to be fatal; large deletions are usually fatal - there are always variations based on which genes are lost. Some medium-sized deletions lead to recognizable human disorders, e.g. Williams syndrome.
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. In contrast, a deletion that is evenly divisible by three is called an in-frame deletion.
Deletions are responsible for an array of genetic disorders, including some cases of male infertility and two thirds of cases of Duchenne muscular dystrophy. Deletion of part of the short arm of chromosome 5 results in Cri du chat syndrome. Deletions in the SMN-encoding gene cause spinal muscular atrophy, the most common genetic cause of infant death.
Recent work suggests that some deletions of highly conserved sequences (CONDELs) may be responsible for the evolutionary differences present among closely related species. Such deletions in humans are referred to as hCONDELs may be responsible for the anatomical and behavioral differences between humans,chimpanzees and other mammals.
Read more about this topic: Deletion (genetics)
Famous quotes containing the word effects:
“Perspective, as its inventor remarked, is a beautiful thing. What horrors of damp huts, where human beings languish, may not become picturesque through aerial distance! What hymning of cancerous vices may we not languish over as sublimest art in the safe remoteness of a strange language and artificial phrase! Yet we keep a repugnance to rheumatism and other painful effects when presented in our personal experience.”
—George Eliot [Mary Ann (or Marian)
“Let us learn to live coarsely, dress plainly, and lie hard. The least habit of dominion over the palate has certain good effects not easily estimated.”
—Ralph Waldo Emerson (1803–1882)
“The machines that are first invented to perform any particular movement are always the most complex, and succeeding artists generally discover that, with fewer wheels, with fewer principles of motion, than had originally been employed, the same effects may be more easily produced. The first systems, in the same manner, are always the most complex.”
—Adam Smith (1723–1790)