Genetics of British Pakistanis

Happy Friday! I’ve been thinking about underrepresentation of South Asian population in growing genomic databases. Although the situation is still bad—South Asians continue to be underrepresented in genome-wide association studies—it is better than before. There are many locally-led efforts such as Pakistani Genomics Resource, GenomeAsia 100k consortium etc. that are stretching their arms to fill the big diversity gap. But there are also many efforts in the UK and US, where researchers are building South Asian genetic cohorts by recruiting Brits and Americans of South Asian origin, respectively. One such cohort is Genes and Health, a mini UK Biobank of South Asians in the UK, which has been recruiting British-Pakistanis and British-Bangladeshis for several years now with the goal of reaching 100,000 participants in the next few years. For this week’s From the Twitter archives post, I highlight a Twitter thread I wrote two years ago on one of the many interesting works that came out of the Genes and Health study.

From the Twitter archives

This is an important work from Elena Arciero, Hilary Martin and colleagues from Wellcome Sanger Institute, UK on the fine-scale population structure and demographic history of British Pakistanis

I am glad I stumbled upon this while I am in India visiting family after a long time and, as usual, contemplating about my culture and the impact it had on my genes.

South-Asian populations have rich and complicated cultural histories, traces of which can be found in today's south-Asian genomes (something that scares the South-Asian me, but fascinates the geneticist me).

Here, the authors studied the genetic structure of 2,200 British Pakistanis of South Asian ancestry, "one of the largest and most socioeconomically disadvantaged ethnic minorities in the UK".

Like Indians, Pakistanis also identify themselves in distinct caste communities, which determine their social status in the community. People marry only within their community and this endogamy is being practiced for hundreds of years, and it is believed to have become stronger during the British rule.

These hundreds of years of endogamous practices have populated South-Asians’ genomes with numerous recessive mutations, making them the world's best population to mine for human knockouts.

Endogamy can be genetically quantified using IBD scores (number of segments of genome that are identical across two or more individuals, hence come from a common recent ancestor), which will