All of Us published the results from almost 250,000 genome sequences in a recent issue of Nature (All of Us Research Program Investigators, 2024). They found one billion variants of which 275 million had not been seen before.
Recall that the UK study (UK Biobank) emphasized the importance of variation in determining whether a given region of DNA was functional or not. They noted that regions that were constrained (i.e. fewer variants) were likely under purifying selection whereas regions that accumulated variants were likely junk [Identifying functional DNA (and junk) by purifying selection]. Their results indicated that only about 10% of the genome was constrained and that's consistent with the view that 90% of our genome is junk. The American study did not address this issue so we don't know how it related to the junk DNA controversy.
Note that if 90% of our genome is junk then that represents 2.8 billion base pairs and the potential for more than 8 billion variants in the human population.1 Some of these will be quite frequent in different groups just by chance but most of them will be quite rare. We'll have to wait and see how this all pans out when more genomes are sequenced. The idea of increasing the detection of unusual variants by sequencing more diverse populations is a good one but the real key is just more genome sequences.
One of the things you can do with this data is to cluster the variants according to the self-identified ethnic group of the participants and All of Us didn't hesitate to do this. They even identified the clusters as races, proving once again that there are clear genetic diffences between these groups, just as you would expect. Given the sensitive nature of this fact, you would also expect a lot of criticism on the internet and that's what happened.
1. I'm defining a "variant" as a difference from the reference genome sequence. I'm aware of the terminology issue but it's not important here. There will also be a large number of variants in the functional regions.
All of Us Research Program Investigators (2024) Genomic data in the All of Us Research Program. Nature 627:340. [doi: 10.1038/s41586-023-06957-x].