Are There Genetic Markers for Alcoholism in African Populations?

April 26, 2016

The use and overuse of both legal and illegal substances is becoming a chronic health concern in Kenya as in most countries around the world. Whether sold over the counter like alcohol and cigarettes, or illicitly like cannabis, the perils of abuse are more than just a social concern: they are becoming a real public health menace.

Alcoholism has repeatedly been shown to be a disease, with genetic markers (Mayfield, Harris, & Schuckit, 2008). But what about use of other substances? Can their overuse or abuse be traced to heredity as well?

There have been some studies drawing a correlatory link between genetic variations, or polymorphisms, for drugs and dependence, though these have largely been confined to European, North American and Asian populations.

The high toll that alcohol and drug overconsumption takes on African populations – whether the illegal brews known here in Kenya as changa’a or that which comes labeled and in bottles – make it a priority for us to look at African populations to uncover whether there are similar links in our own genetic makeup.

The African Population and Health Research Center (APHRC) is implementing the “Africa, Wits-INDEPTH Partnership for Genomic studies (AWI-Gen project) on Genomic and Environmental Risk Factors for Cardiometabolic Disease in Africans. This study is trying to understand the interplay between genetic, epigenetic and environmental risk factors for obesity and related cardio metabolic diseases (CMD) in sub-Saharan Africa. The project capitalizes on the unique strengths of existing longitudinal cohorts and well-established health and demographic surveillance systems (HDSS) run by the partner institutions in four countries: Kenya, South Africa, Ghana and Burkina Faso.

There are six study sites across these four countries representing geographic and social variability of African populations which are also at different stages of the demographic and epidemiological transitions. APHRC is implementing this project in Kenya within the Nairobi Urban Health and Demographic Surveillance Site (NUHDSS). This is part of the broader work done by APHRC on non-communicable diseases (NCDs) in Kenya and across sub-Saharan Africa.

There is evidence showing that genetic and environmental factors play a role in the development of alcoholism with more recent findings demonstrating that processes related to genetic factors that do not manifest as DNA sequence changes (i.e., epigenetic processes) also play a role. However very little is known about the situation in sub-Saharan African populations. The project is funded under the Human Heredity and Health in Africa (H3Africa) initiative, seeking to build sustainable capability for genomic and genetic research on the African continent; investigate and understand genome structure in sub-Saharan African populations; and identify genetic variants that influence body composition and contribute to susceptibility for cardio metabolic disease. The goal of this groundbreaking initiative is to support Africa’s own development of capacity to carry out these kinds of studies in populations around the continent, in order to better understand the genetic and genomic markers for disease including alcoholism.

With recent studies having demonstrated that the amount of alcohol one consumes and progression to alcoholism have genetic influence (Kendler, Gardner, & Dick, 2011), the capacity to understand genetic and genomic markers of diseases by African scientists would lead to further research interrogating whether drug use and abuse are genetically linked.  This could lead to an evidence-based approach to control drug use and abuse that fit the African context – and help the continent do more to eliminate one of the four main risk factors for non-communicable disease.

What needs to be done?

Kenya needs targeted, sustainable and cost-effective approaches to the challenge of increased drug and alcohol use among its population. As a nation it is clear that we are deeply concerned about the effect that alcohol and drugs can have on productivity, economic development and the health of our young population.

We need Kenya-specific research that interrogates the hypothesis that alcoholism is a disease, with the possibility of genetic markers. This base of evidence could help transform the way we treat alcohol use and abuse: as a disease rather than as a failure or weakness of spirit.

Confining our action to symptomatic treatment only, without addressing the etiology of alcoholism, will not suffice. It would be like shutting down one party, only to have the merrymakers move down the street to start another one. If we want long-term solutions to respond appropriately to the disease of alcoholism, we must look beyond reducing the supply of illegal brews as the end point, and address the reason(s) why there is such a high demand for alcohol in our society. And only then will we as a nation be able to develop the right plan of action for reducing the health consequences of alcohol and drug abuse in this country.