Segment, genomic : A region of the genome; it encompasses objects described as loci or probes. Genomic segments can range in size from points to regions as large as an entire chromosome.

There are many types of genomic regions. On a technical level, they include genes, gene elements, amplimers (PCR markers), breakpoints in chromosomes, clones, cytogenetic markers, fragile sites on chromosomes, expressed sequence tags (ESTs), syndromic regions, contigs and DNA repeats.