Genetics, Mutagenesis

Excerpt

Mutagenesis is the process of an organism's deoxyribonucleic acids (DNA) change, resulting in a gene mutation. A mutation is a permanent and heritable change in genetic material, which can result in altered protein function and phenotypic changes. DNA consists of nucleotides that contain a phosphate backbone, a deoxyribose sugar, and 1 of 4 nitrogen-containing bases (adenine [A], guanine [G], cytosine [C], and thymine [T]). DNA mutagenesis occurs spontaneously in nature or as a result of mutagens (agents predisposing to alter DNA). Furthermore, molecular genetic techniques, such as polymerase chain reaction (PCR), have revolutionized how mutations are obtained and studied. Mutagenesis is the driving force of evolution; however, it can also lead to cancers and heritable diseases (See Image. Genome Editing).

Single base-pair substitutions are the most common cause of human pathology. An example is sickle cell disease, where a single base-pair mutation results in substituting glutamate to valine amino acid. Otherwise, human disease results from various insertions, deletions, duplications, inversions, expansions, fusions, and complex rearrangements. For example, a CGG repeat expansion in the FRM1 gene causes fragile X syndrome, while a fusion protein BCR-ABL results in chronic myeloid leukemia (CML).