Talking Glossary of Genetic Terms

Duplication

Duplication is a type of mutation that involves the production of one or more copies of a gene or region of a chromosome. Gene and chromosome duplications occur in all organisms, though they are especially prominent among plants. Gene duplication is an important mechanism by which evolution occurs.

Narration Transcription

Duplications occur when there is more than one copy of a specific stretch of DNA. This can occur in several different contexts. During a disease process, extra copies of the gene can contribute to a cancer. Genes can also duplicate through evolution, where one copy can continue the original function and the other copy of the gene produces a new function. On occasion, whole chromosomes are duplicated. In humans this causes disease. Throughout evolution, there have been several occasions, both in fish and plants, where whole genomes have been duplicated.

Doctor Profile

Name: Lawrence C. Brody, Ph.D.

Occupation: Chief & Senior Investigator, Genome Technology Branch; Head, Molecular Pathogenesis Section

Biography: Dr. Brody investigates the genetics of breast cancer and neural tube defects. As chief of the NHGRI Genome Technology Branch's Molecular Pathogenesis section, he is interested in studying genetic mutations that lead to perturbations in normal metabolic pathways and cause disorders such as cancer and birth defects. His laboratory investigates mutations in two breast cancer-linked genes, breast cancer gene 1 (BRCA1) and breast cancer gene 2 (BRCA2). Dr. Brody's laboratory was among the first to report that women carrying BRCA1 or BRCA2 mutations have a higher risk of developing both breast and ovarian cancer than women without such mutations.