14q

14q refers to the long arm of human chromosome 14, as used in human cytogenetics to describe the location of genes and chromosomal abnormalities. The designation 14q32, for example, identifies a specific region on the long arm that is frequently involved in imprinting, deletion, duplication, and translocation events. Abnormalities of 14q can contribute to developmental disorders, congenital anomalies, or cancer, depending on the exact region affected and the nature of the rearrangement.

A notable region is 14q32, which contains a large imprinted gene cluster including DLK1 and MEG3, among others. Disturbances of this imprinting domain give rise to imprinting disorders such as Kagami-Ogata syndrome (paternal uniparental disomy or duplications of 14q32) and Temple syndrome (maternal UPD or epimutations). The region also harbors the immunoglobulin heavy chain locus (IGH) at 14q32, which is a frequent breakpoint in chromosomal translocations involved in lymphoid cancers.

In cancer genetics, a classic translocation is t(14;18)(q32;q21), which juxtaposes the IGH enhancer on 14q32 with the BCL2 gene on 18q21, leading to overexpression of BCL2 and the development of follicular lymphoma. Deletions or duplications of 14q material are also observed in various congenital and neurodevelopmental disorders, often detected by karyotype analysis or chromosomal microarrays.

Diagnosis and testing for 14q abnormalities rely on cytogenetic methods such as karyotyping, fluorescence in situ hybridization, and array-based techniques to identify the precise structure and genes involved, informing prognosis and management where applicable.