chr14·hg38·107.0 Mb

Chromosome 14

The immunoglobulin heavy chain chromosome — where adaptive immunity is assembled, where lymphomas are born, and where reciprocal imprinting syndromes reveal the tug-of-war between maternal and paternal genomes.

Physical Properties

Length107.0 Mb

Centromeresubmetacentric

p-arm16.0 Mb

q-arm88.9 Mb

GC content40.9%

Genomic Features

Protein-coding genes830

Gene density7.8 / Mb

CpG islands10,275

EPIC v2 probes32,990

Notable

Largest geneNRXN3 (1.7 Mb)

Disease associations

Burkitt lymphoma

Multiple myeloma

FOXG1 syndrome

· Houses the immunoglobulin heavy chain locus (1.25 Mb)

· Acrocentric — contributes to Robertsonian translocations

· t(8;14) IGH-MYC drives Burkitt lymphoma

Genomic Architecture

The short arm (14p) shares extensive segmental duplications with other acrocentric chromosomes, including homologous sequences that facilitate Robertsonian translocations

The pericentromeric region of 14q11 contains segmental duplications harboring the T-cell receptor alpha/delta (TRA/TRD) locus, where V(D)J recombination generates enormous somatic diversity

Interchromosomal duplications link 14q11 with paralogous regions on chromosomes 2 (TRB) and 7 (TRG)

Evolutionary History

Chimpanzee — Human chromosome 14 corresponds to chimpanzee chromosome 15

Gorilla — Maintains the same syntenic block

Deep Cuts

The nested receptor — The T-cell receptor delta (TRD) locus is physically embedded within the T-cell receptor alpha (TRA) locus at 14q11.2 — one locus inside another. When a developing T cell commits to the alpha-beta lineage, it literally…

Healthy lymphoma carriers — The t(14;18) translocation, which drives follicular lymphoma by activating BCL2, is detectable by PCR in 50-70% of healthy adults' peripheral blood. These individuals carry small clones of cells with the translocation…

The imprinting mirror — Kagami-Ogata syndrome (paternal UPD14) and Temple syndrome (maternal UPD14) are phenotypic opposites controlled by the same 14q32 locus. Paternal UPD causes overgrowth features (large placenta, polyhydramnios, abdomin…

§ Deep dive

The short arm (14p) shares extensive segmental duplications with other acrocentric chromosomes, including homologous sequences that facilitate Robertsonian translocations

The pericentromeric region of 14q11 contains segmental duplications harboring the T-cell receptor alpha/delta (TRA/TRD) locus, where V(D)J recombination generates enormous somatic diversity

Interchromosomal duplications link 14q11 with paralogous regions on chromosomes 2 (TRB) and 7 (TRG)

LINEsSlightly below genome average, consistent with the moderate GC content

SINEs/AluNear genome average, with enrichment in the gene-dense 14q32 region

Satellite DNAThe short arm contains alpha-satellite (centromeric), beta-satellite (proximal junction), and satellites I/II/III in the pericentromeric heterochromatin

The T2T assembly revealed that 14p contains approximately 3-4 Mb of rDNA arrays, though copy number varies dramatically between individuals (from ~10 to ~100+ copies per chromosome)

FRA14B(14q23): Aphidicolin-sensitive common fragile site; maps within the large FERM domain-containing protein gene FRMD6

FRA14C(14q24.1): Coincides with a region of recurrent deletions in various cancers