chr14 · 14q13.1 · 265 nt · 2025
HAR202
NPAS3 cluster
Anomaly
5.80
Genes
NPAS3
Length
265 nt
What it is
HAR202 lives in NPAS3, a gene that helps build and balance neural circuits. The 2025 single-cell CRISPR study found that the human-specific letters attenuate NPAS3 — a quieter switch, not a new protein.
Why it matters
Causal HAR→NPAS3 attenuation.
Operator load
01 · ΔE
Enhancer activity
These stretches of DNA do not code for proteins. They act as volume knobs — turning nearby brain-development genes up or down at the right moment.
03 · T
Three-dimensional rewiring
The genome folds in 3D. Human-specific changes can re-route which switches sit next to which genes, even if the letters look similar in a straight line.
06 · P
Population spread
Once a change is useful, it spreads. Many HAR variants rose quickly in ancestral humans and are now nearly fixed across living populations.
Cui et al. Nature 2025 · Kamm et al. 2013
Same neighborhood
- HAR2 / NPAS3 — NPAS3 hosts the largest HAR cluster in the genome — a transcription-factor locus that helps build and balance neural circuits.
- HAR21 — A human-accelerated enhancer sitting inside NPAS3 itself — a switch embedded in the gene it helps control.