POLYMER GENOMICSchr8·hg38·145.1 Mb
Atlas
Open chr8 in viewer Chromosome 8
The first autosome sequenced from telomere to telomere — whose vast regulatory desert orchestrates cancer at a distance, whose centromere reveals the geological record of primate evolution, and whose short arm carries an inversion shared by a quarter of humanity.
Physical Properties
Length145.1 Mb
Centromeresubmetacentric
p-arm44.0 Mb
q-arm99.8 Mb
Genomic Features
Protein-coding genes683
Gene density4.7 / Mb
CpG islands11,439
EPIC v2 probes43,413
Notable
Largest geneCSMD1 (2.1 Mb)
Disease associations
Burkitt lymphoma
Bladder cancer
Pfeiffer syndrome
· MYC at 8q24 is one of the most amplified oncogenes in cancer
· t(8;14) MYC-IGH translocation defines Burkitt lymphoma
· 8q24 desert region contains multiple GWAS cancer risk loci
Genomic Architecture
8p23.1 inversion polymorphism — 3.8-4.5 Mb segment exists in two orientations in ~26% of individuals. Flanked by olfactory receptor/defensin clusters (REPD/REPP). Can predispose to invdupdel(8p) rearrangements.
Beta-defensin CNV — 644-kb copy-number-variable cluster (DEFB4, DEFB103, DEFB104). Copy number ranges 1-12 per haploid genome. Low copy number (<=3) confers 3x increased Crohn disease risk.
8q24 gene desert — ~1.8 Mb nearly devoid of coding genes, yet one of the most important regulatory landscapes in the genome — harbors more cancer GWAS risk SNPs per Mb than almost any other region.
Evolutionary History
First complete autosome — First T2T autosome (2021), third completed centromere (after X and Y).
Centromere evolution — Comparative assembly revealed layered, mirrored symmetry — more ancient HOR repeats pushed to periphery while newer occupy functional center, like geological strata.
Deep Cuts
The 8q24 "desert" is an oasis — One of the most transcriptionally active non-coding regions, producing multiple lncRNAs and miRNAs.
PVT1 is MYC's essential co-conspirator — Mouse models show MYC gain alone is insufficient for tumorigenesis without PVT1.
The 8p23.1 inversion is invisible — Present in ~26% of the population, this 4.5 Mb inversion is cytogenetically indistinguishable from the direct orientation.
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