A segment of DNA that encodes for a particular polypeptide. That is, the DNA sequence that contains the biological instructions for the production of a polypeptide chain, usually a specific protein or component of a protein.
Use in clinical context
Genes are key to cellular form and function. Changes within genes can lead to the molecules they code for not functioning correctly, or not being formed. Most functional variants in the genome that have been identified are within genes. The majority of rare diseases are caused by variants in genes.