NCI Dictionary of Genetics Terms

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Welcome to the NCI Dictionary of Genetics Terms, which contains technical definitions for more than 150 terms related to genetics. These definitions were developed by the PDQ® Cancer Genetics Editorial Board to support the evidence-based, peer-reviewed PDQ cancer genetics information summaries.

5 results found for: E
epigenetic alteration
(EH-pih-jeh-NEH-tik ALL-teh-RAY-shun)
A heritable change that does not affect the DNA sequence but results in a change in gene expression. Examples include promoter methylation and histone modifications. Also called epimutation.
epigenetics
(EH-pih-jeh-NEH-tix)
The study of heritable changes that do not affect the DNA sequence but influence gene expression.
epimutation
(EH-pih-myoo-TAY-shun)
A heritable change that does not affect the DNA sequence but results in a change in gene expression. Examples include promoter methylation and histone modifications. Also called epigenetic alteration.
ER-negative PR-negative HER2/neu-negative breast cancer
(... NEH-guh-tiv ... NEH-guh-tiv ... NEH-guh-tiv brest KAN-ser)
ER-negative PR-negative HER2/neu-negative breast cancer is defined by a lack of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2/neu). Also called triple-negative breast cancer.
exon
(EK-son)
The sequence of DNA present in mature messenger RNA, some of which encodes the amino acids of a protein. Most genes have multiple exons with introns between them.