Genomics research consortium · BEGINNER LESSON
1000 Genomes Project
The 1000 Genomes Project was an international research consortium that sequenced the genomes of volunteers from multiple populations to build a public catalogue of human genetic variation. Its goal was to measure common and rare DNA differences across people and populations, not to study one disease in one person.
What it is and what was measured
The 1000 Genomes Project measured genetic variation in human DNA, meaning differences in the sequence of the genome from one person to another. It used whole-genome sequencing, deep exome sequencing, and SNP microarrays to find variants across populations. In the final phase, it produced an open-access database from 2,504 individuals in 26 populations worldwide. [Source 0, 1, 2]
[1] The 1000 Genomes Project: Welcome to a New World - PMC - NIH [2] [PDF] The 1000 Genomes Project: [3] [PDF] Expanding diversity in genomics
How it worked
The project compared many people’s DNA to the human reference genome and organized the results into a catalogue of variants. A variant is a DNA site where some people differ from the reference sequence. The project recorded SNPs, which are single-letter DNA changes, indels, which are short insertions or deletions, and structural variants, which are larger DNA changes. It also placed variants into haplotype context, meaning it tracked which variants tend to be inherited together on the same chromosome. [Source 0, 1]
[1] The 1000 Genomes Project: Welcome to a New World - PMC - NIH [2] [PDF] The 1000 Genomes Project:
Why it mattered
The data were designed to support population genetics and disease studies. For example, they helped improve genotyping arrays, genotype imputation in GWAS (genome-wide association studies), and the search for likely neutral and functional variants. The project also helped researchers study natural selection, population structure, and admixture, while improving the human reference sequence. [Source 0, 1]
[1] The 1000 Genomes Project: Welcome to a New World - PMC - NIH [2] [PDF] The 1000 Genomes Project:
What the results showed
The project found more than 88 million variants in total. A typical human genome differs from the reference at about 4 to 5 million sites, and most of those differences are SNPs and short indels. The studies also reported that African-ancestry individuals had the greatest number of variant sites, and that many common variants are shared globally while rarer ones are often limited to related populations. [Source 0, 2]
[1] The 1000 Genomes Project: Welcome to a New World - PMC - NIH [3] [PDF] Expanding diversity in genomics
Limitations and caveats
The project did not capture every possible human variant in every person, and the reference genome itself can miss sequence found in other people. The public catalogue is extremely useful, but it still supports follow-up studies rather than replacing them. Some findings are frequency-based, so rare variants can still be missed if they are not present in the sampled groups. [Source 0, 1]
[1] The 1000 Genomes Project: Welcome to a New World - PMC - NIH [2] [PDF] The 1000 Genomes Project:
SEE THE IDEA
How the 1000 Genomes Project built a variant catalogue
DNA from people in multiple populations was collected for study.
Whole-genome sequencing, exome sequencing, and SNP arrays were used to detect differences.
Software tools identified SNPs, indels, and structural variants and checked them against the reference genome.
The results were organized into an open-access catalogue for later genetic studies.
Samples flowed from people to DNA measurement to variant analysis to a shared public resource.
The project measured human DNA differences across many populations and turned them into a searchable catalogue.
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Sources and further reading
This general lesson was generated from public source material. It explains a concept; it does not interpret a private paper or provide medical advice.