Monday, 17 October 2016 11:03

The need for diversity in genomic data

Genomic research calls for broader genetic representation to ensure future healthcare could be truly personalised

The bedrock of personalised medicine is our growing capacity to sequence and compare genomic DNA to identify the genetic changes that cause or increase the risk of disease. Finding out which genetic changes are part of ‘normal’ genomic variation between individuals and which variants may play a role in disease risk or responses to treatment is still not easy, but our knowledge and understanding grows all the time.

However, there is a problem: many existing genomic research efforts lack diversity. Most participants in large-scale studies intended to link genetic variants with disease risks (genome-wide association studies or GWAS) are of European descent. Genetic differences do exist between groups of people from different ethnic origins; without knowing what is ‘normal’ for each population, it may not be possible to spot crucial genetic variants that affect health, and any findings in one population may be less applicable in others.

Progress for Asian populations

In 2009, an analysis showed that the proportion of non-European GWAS participants worldwide was just 4%. New data shows that this has risen to 26%, primarily from a rapid increase in research involving Japanese, Chinese, Korean, Indian and other Asian populations. The GenomeAsia100K project was launched earlier this year to sequence and analyse whole genomes from 100,000 Asian individuals, to drive the development of precision medicine for Asian populations, which constitute over 40% of the world population.

Closer to home, the East London Genes & Health study is linking medical and genomic data from 100,000 people of South East Asian origin. East London has large Bangladeshi and Pakistani populations with relatively poor health in comparison with the rest of the local population, including a five-fold higher rate of diabetes. Tackling this health inequality is very important, and understanding the genetics at play is undoubtedly part of the answer.

A wider view

Major research funders are starting to recognise the importance of population diversity in large-scale genomic research. Representation of people of African, Latin American and Hispanic ancestry (all common in the US population, for example) remains very low, as it is for indigenous peoples, who may have particularly distinct genomic profiles and health issues.

However, efforts to combat this under-representation are underway, such as the Human Heredity and Health in Africa Initiative. H3Africa is a joint venture of the US National Institute of Health, the UK Wellcome Trust, and the African Society of Human Genetics, examining both genomic and environmental factors affecting the risk of common diseases and response to medicines in African populations, to deliver better health. Global DNA sequencing company Illumina, the leading commercial partner of the UK’s own 100,000 Genomes Project, has announced the development of a useful new genomic research tool. The H3Africa microarray detects a total of 2.5 million genetic variants designed to include those common among African populations.

Eventually, achieving suitable diversity in genomic research will hopefully make it possible to deliver effective personalised medicine by taking into account the most accurate genetic information to assess disease risk, prevention and treatment for a given individual – whatever their ethnic background.