Platform
All genotyping is performed on Illumina bead arrays by our sequencing partners in Singapore, Hong Kong, Japan and South Korea: GSA v3 with Malaysian custom content, GSA v2/v3, and the Asian Screening Array.
The array for each batch is established from the number of markers in the delivered genotype file, not from the text of the accompanying report, because a marker count cannot be mislabelled and the reports are inconsistent.
Measured quality
98.48% median call rate. The individuals below a 95% call rate are flagged for review before use rather than quietly included, and the count is republished with every release.
Where the laboratory's own figure was not retained, the call rate was recomputed directly from that person's genotype file, and the record says which.
Chain of custody
One folder per laboratory delivery, 302 of them, each carrying its order number, date, platform, the evidence for that platform, per-individual quality, and a SHA-256 for every file in it.
Raw scanner output is retained wherever it was supplied, so genotypes can be re-called from the original instrument measurement if a manifest is ever revised.
Integrity
All 28,171 archive files were fingerprinted with SHA-256. Re-running the verification re-reads every file and reports anything that differs, is missing, or is new.
That is the difference between saying the data is unaltered and demonstrating it.
Ancestry labels
The grouping is measured; the names are provisional. Groups come from principal component analysis over roughly 17,000 markers followed by clustering, with no labels used. The names attached to them are inferred from two anchor markers.
Confirming them means projecting reference populations into the same space, and no Malay or Austronesian population exists in 1000 Genomes, so a separate reference is needed. Sound for deciding which markers merit attention. Not sufficient on its own for publication.
One Chinese group, and the split that was not real
An earlier build of this page showed two Chinese clusters. They were never two populations, and they are gone. Outside the MHC region of chromosome 6 they agreed to within five percentage points at more than 99.9% of markers and carried the East Asian anchor markers equally; inside it they diverged wildly. At rs9262570, the HLA-B*58:01 tag, each cluster alone was far from Hardy-Weinberg proportions (chi-square 434 in the smaller one) while the two combined were in balance (0.2).
The cause was our own method. The clustering was reading the MHC, where hundreds of markers travel together as one haplotype, and in effect sorted Chinese participants by whether they carry it. Standard practice is to leave that region out, along with the other regions of long-range linkage disequilibrium listed by Price and colleagues (2008). Since 26 September 2026 the grouping does exactly that, and also thins markers that are close together and strongly correlated. One Chinese group results, and no component of the analysis follows the MHC any more.
The markers in the MHC region are still left out of the counts that compare groups: those probes are the hardest on any array, and that exclusion is stated wherever the counts appear.
Privacy
The published data holds no personal identifiers. Records that do identify people are kept in a separate restricted area and excluded from every research output.
Nothing derived from fewer than 20 individuals is published anywhere, following the practice of the NIH All of Us programme. No individual-level data exists in the files behind this page.
Our Data Protection Officer, , answers any question about how this data is held: . See Data protection.
Genome build
Positions are given in GRCh38 by default and labelled as such, with the GRCh37 coordinate shown alongside.
The same marker has different coordinates in the two builds, and mixing them is a common and silent source of wrong results.