13q13

13q13 is a cytogenetic band on the long arm of human chromosome 13. In the standard nomenclature used by clinical and research cytogenetics, 13q13 denotes a defined region within the q arm that helps describe the location of chromosomal breakpoints, duplications, deletions, or translocations. The exact boundaries and the set of genes present in this band can vary depending on the genome annotation used, but the designation serves as a stable reference point for reporting structural variation involving chromosome 13.

Alterations that involve the 13q13 region have been reported in various contexts, including congenital disorders and cancer. The clinical significance of such changes depends on the size of the rearrangement and which genes are affected; broader deletions or duplications spanning 13q13 can disrupt multiple genes and lead to a range of phenotypes. Isolated changes confined strictly to 13q13 are less commonly described, and their effects, when present, may show variable expressivity and penetrance.

Detection and analysis of 13q13 abnormalities rely on standard cytogenetic and molecular techniques. Karyotyping can identify gross rearrangements at the band level, while fluorescence in situ hybridization (FISH), chromosomal microarray analysis (CMA), and next-generation sequencing enable more precise breakpoint mapping and gene-level interpretation.

See also: Chromosome 13, 13q deletion syndrome, Cytogenetic band nomenclature. Further reading includes cytogenetics databases and reviews on structural variation of chromosome 13.