The human DNA is exposed to a number of changes, these changes are frequently carried out in one or few nucleotides called mutations, which can be caused by errors in the mechanisms of DNA replication and repair as well as by environmental factors; and these mutations can have deleterious effects and cause disease. These mutations can result in polymorphisms that provide allelic variation between individuals and diversity of species; to be considered as such its frequency should be higher in one of its alleles at 1%.