A new international consortium of blood genetics has been created by a team at the University of Montreal. Unlike previous data sets that severely under-represent non-European populations, this consortium examined five major global populations.
The team led by Professor Guillaume Lettre wanted to see if genetic differences had an effect on certain blood characteristics. By examining European, African, Hispanic, East Asian and South Asian populations for 15 blood traits, significant differences were found that have potential implications for haematological diseases.
The 15 blood traits chosen covered the cell counts and sizes of red and white blood cells, along with haemoglobin concentrations and platelet volume.
From this analysis of 746,667 participants and testing of 45 million variations, 5,500 associations were discovered to impact the chosen blood characteristics – 71 of which were not found in European populations.
Despite the global reach of this study, the vast majority of participants were of European ancestry, over 75%, with only 2% of participants in the Hispanic and South Asian group. This introduced a European bias to the study. Although this was enough to identify unique variants, such as an interleukin IL7 missense variant, that increases lymphocyte count in South Asians.
This highlights the need for more global representation in genetic studies, to identify more causal variants not found in European populations. Genome-wide association studies that do include multi-ethnic groups have been recognised as more powerful and useful for gene-mapping.
