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Study explores rheumatic heart disease susceptibility in African individuals

A new study has revealed a novel candidate susceptibility locus that is exclusive to Black African individuals and is an important heritable component to rheumatic heart disease (RHD) susceptibility in Black Africans.

Titled Association of Novel Locus with Rheumatic Heart Disease in Black African Individuals, and published on the online medical publication JAMA Network , the paper is written by a team of researchers within the Genetics of Rheumatic Heart Disease (RHDGen) Network – a project within the Human Heredity and Health Africa (H3Africa) consortium.

The study set out to identify common genetic loci associated with RHD susceptibility in African individuals.

Tafadzwa Machipisa, a doctoral student based in the Department of Medicine at the University of Cape Town and the lead author on the paper says: “Our findings may provide insight as to why RHD is even more common in Black Africans than in previously studied populations. Our results will further allow interstudy analyses to get the bigger picture on a global population scale, to find global solutions to the RHD epidemic.”

The genome-wide association (GWAS) study involved 4809 African participants from eight African countries – Kenya, Mozambique, Namibia, Nigeria, South Africa, Sudan, Uganda, and Zambia. The participants were screened using echocardiography – a non-invasive diagnostic test that uses high-frequency sound waves to produce images of the heart – and provided DNA samples. The analysis of the data took place between May 15 2017 and March 14 2021. The GWAS identified a single novel RHD risk locus, 11q24.1, which had genome-wide significance in Black African individuals.This study also reveals an important polygenic component to RHD risk in African individuals.

Rheumatic heart disease is caused by permanent damage to the heart valves and it is the leading cause of cardiac surgery in Africa. Despite being widespread, especially in resource-challenged environments, the understanding of RHD’s characteristics and genetics are still not well understood.

The study concludes that understanding genetic susceptibility may aid in prevention, control, and interventions that can lead to eliminating RHD.

In conclusion, Machipisa says: “I would like to thank my PhD supervisors Profs Guillaume Paré, Mark Engel, Bernard Keavney, and the late Prof Bongani Mayosi for their guidance and support, as well as the H3Africa Fellows club for their educational events and activities.”

Read the full paper on the JAMA Network here