20q12

20q12 is a cytogenetic band located on the long arm (q) of human chromosome 20. The designation refers to the position of chromosomal material as seen on a G-banded karyotype, with the q arm being the longer arm and the number 12 identifying a specific region within that arm. Because cytogenetic bands are defined by staining patterns, the exact base-pair coordinates vary between genome assemblies, so 20q12 serves as a descriptive location rather than a fixed sequence.

In clinical cytogenetics, the 20q12 region can be involved in structural rearrangements such as deletions, duplications, or translocations that extend into or originate from that part of chromosome 20. Its interpretation often relies on molecular techniques such as fluorescence in situ hybridization (FISH) or array comparative genomic hybridization (array CGH) to characterize the extent and content of the abnormality.

The 20q12 region contains multiple genes, but specific causal relationships between alterations in this band and particular diseases are not as well established as for some neighboring regions. Variants involving chromosome 20, including broader portions of the 20q arm, have been studied in various cancers and developmental disorders, though smaller or isolated abnormalities at 20q12 are less frequently reported as definitive disease drivers.

See also: chromosome 20, cytogenetic banding, 20q11, 20q13.1.