In human genetics, the complete set of protein-coding regions in a genome is called the exome.
The exome consists mainly of exons, the portions of genes that remain in mature messenger RNA after introns are removed. Although exons make up only a small fraction of the human genome, changes in them can directly alter protein sequences. For this reason, whole-exome sequencing is widely used to investigate suspected inherited disorders.
The exome is not the same as the entire genome. A whole-genome sequence includes protein-coding regions, noncoding DNA, regulatory sequences, repeated elements, and other genomic material. The exome also does not equal the proteome, which is the collection of proteins produced by a cell, tissue, or organism.
Exome sequencing can identify disease-causing variants, but it has limits. It may miss changes in deep noncoding regions, some structural variants, and alterations that are difficult to detect technically. A negative exome result therefore does not exclude a genetic diagnosis.