Genetic insights into smoking behaviours in 10,558 men of African ancestry from continental Africa and the UK

Abstract

Smoking is a leading risk factor for many of the top ten causes of death worldwide. Of the 1 billion smokers globally, 80% live in low- and middle-income countries, where the number of deaths due to tobacco use is expected to double in the next decade according to the World Health Organization. Genetic studies have helped to identify biological pathways for smoking behaviours, but have mostly focussed on individuals of European ancestry or living in either North America or Europe. Here we present a genome-wide association study of two smoking behaviour traits in 10,558 men of African ancestry living in five African countries and the UK. Eight independent variants were associated with either smoking initiation or cessation at p-value < 5 x 10-6. Of these, four were monomorphic or rare in European populations. Gene prioritization strategy highlighted five genes, including SEMA6D, previously described as associated with several smoking behaviour traits. These results confirm the importance of genetic epidemiological studies in underrepresented populations.