The complete sequence of a human genome
Level 5 - mechanism / opinion, no new human data
Bench research / descriptive genomic assembly (graded by non-clinical design analogy).
OpenAlex W3163990482 · doi:10.1101/2021.05.26.445798
What was done
The Telomere-to-Telomere (T2T) Consortium generated a gapless, complete assembly of a human genome (T2T-CHM13) spanning all 22 autosomes and Chromosome X to resolve the remaining ~8% of the human genome left unfinished or erroneous in prior reference releases.
What was found
The completed reference contains 3.055 billion base pairs (bp). It adds nearly 200 million bp of novel sequence containing 2,226 paralogous gene copies (115 predicted to be protein-coding). The assembly fully resolves complex genomic regions previously missing, including all centromeric satellite arrays and the short arms of all five acrocentric chromosomes.
Why it matters
This provides the first truly complete reference assembly of a human genome, enabling functional and variation analysis across historically inaccessible heterochromatic and repetitive regions.
Limits
The assembly is derived from a single human cell line (CHM13) lacking a Y chromosome, so it does not capture human structural variation or population-level diversity across these newly resolved regions.
Cited by
- supports The completed draft of the Human Genome Project covered approximately 92% of the genome.