First large-scale genome-wide study of blood measurements completed
14 October 2009
Blood measurements, including the number and volume of cells in the blood, are routinely used to diagnose a wide range of disorders, including anaemia, infection and blood cell cancers.
To find genetic variants that influence blood measurements, a UK and German team - including researchers from the Wellcome Trust Sanger Institute - looked at the genomes of over 14 000 people. They found 22 regions of the human genome implicated in the development of blood cells, including 15 that were previously unidentified.
They also discovered one genetic variant associated with platelet counts whose presence increases the risk of developing heart disease. This was found in a region of the genome already known to influence the risk of hypertension, coeliac disease and type 1 diabetes in children and young adults.
"We have uncovered a novel variant linking platelet counts with heart attacks," said Dr Nicole Soranzo, group leader at the Wellcome Trust Sanger Institute and co-lead of the HaemGen consortium that conducted the research.
"Further characterisation of the regions uncovered in this study has the potential to improve our understanding how blood cell development is linked with human diseases, including blood cell cancers."
The researchers measured the concentration of haemoglobin, as well as the number and volume of red and white cells and platelets (the sticky cells that prevent bleeding) from individuals in the UK and Germany.
They then compared regions of the human genome implicated in blood cell development with regions associated with increased risk of heart disease, as well as comparing the genomes of 10 000 people with heart disease with those of 10 000 healthy people.
The genetic risk factors found were strongly linked to European ancestry and the researchers estimate that these became fixed in European genomes around 3400 years ago. They suggest that the risk factors were passed on because they gave carriers an increased protection against infection.
Image: Colour-enhanced scanning electron microscope image of red blood corpuscles. Credit: David Gregory and Debbie Marshall, Wellcome Images
Soranzo NS et al. A genome-wide meta-analysis identifies 22 loci associated with eight hematological parameters in the HaemGen consortium. Nat Genet 2009 [Epub ahead of print].