Edit page | Page history | Printable version

Definition

noun

A type of mutation that involves the loss of genetic material, which may be from a single base to an entire piece of chromosome.

Supplement

Deletion of one or more nucleotides in the DNA could alter the reading frame of the gene; hence, it could result in a synthesis of a nonfunctional protein due to the incorrect sequence of amino acids during translation. In fact, deletion mutations are responsible for many genetic disorders (e.g. [Duchenne muscular dystrophy]) and male infertility. Deletion of a part of the short arm of chromosome 5 results in Cri du chat (“cry of the cat") syndrome in infants.

There are two types of deletion mutation based on the location of deletion in a chromosome: terminal deletion (deletion towards the end of the chromosome) and intercalary deletion (deletion from the interior of a chromosome).

Possible causes of deletion mutation are losses from translocation, chromosomal crossovers within a chromosomal inversion, unequal crossing over, breaking without rejoining, etc.

See also: mutation.