12q22

12q22 is a cytogenetic band on the long arm of chromosome 12. It is one of the defined regions used in human genetics to describe the physical location of genes and chromosomal rearrangements. The band is identified on standard karyotypes by G-banding and is referenced in clinical reports to indicate where a genetic change occurs.

The band corresponds to a segment of the q arm that includes multiple genes and regulatory elements. The exact gene content and boundaries can vary slightly depending on the genome assembly and reference used. As with other cytogenetic bands, 12q22 serves as a coordinate system for describing findings in diagnostic testing and research.

Structural variations affecting 12q22, including deletions, duplications, and translocations, have been reported in a range of conditions. The clinical impact of changes in this region depends on the size of the rearrangement and which genes are involved. Reported associations span neurodevelopmental disorders, congenital anomalies, and, in some contexts, cancer, though the phenotype is often variable and influenced by neighboring genomic material.

Detection and study of 12q22 alterations rely on multiple cytogenetic and genomic techniques. Conventional karyotyping can reveal larger rearrangements, while fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH), and sequencing-based methods can pinpoint breakpoints and define affected gene content with higher resolution.

Genotype-phenotype relationships in the 12q22 region continue to be refined through case reports and larger studies. For practitioners and researchers, 12q22 serves as a reference framework for interpreting structural variants and their clinical significance. For specific gene content or disorder associations, consult databases such as ClinVar, DECIPHER, and OMIM, along with standard cytogenetics references.