Kenya: A massive project on African DNA aims to close the knowledge gap on mental illness

11/17/2020 Ethiopia, Health, World



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In July 2009, a woman brought her husband to the hospital where our colleagues work in western Kenya. She reported that for several years he had been behaving abnormally, sleeping poorly, hearing voices that no one else could hear, and believing that people were talking about him and conspiring to harm him.

She was looking for help because he could no longer work. The man was admitted to the Inpatient Mental Health Unit and diagnosed with schizophrenia.

Then the man’s daughter came to visit him. His clothes and hair were disheveled. She described people who conspired against her and gave her bad looks when she walked down the street. He said he was having trouble sleeping. The doctors looked at each other apprehensively: Is it possible that she also has schizophrenia?

Ultimately, the daughter and four other family members were diagnosed with schizophrenia. While it is rare for six members of the same family to be diagnosed with schizophrenia, it has long been recognized that mental disorders can be inherited. And often members of these families differ in their symptoms.

For reasons we are only beginning to understand, a family member may be diagnosed with schizophrenia and another bipolar disorder or depression. In Eldoret, Kenya, where this health facility is located, it is not unusual to have two or three family members receiving care for mental illness.

Such an occurrence is not unique. Research has found that serious mental illnesses are influenced by genes more than any other risk factor. And genes are emerging as important clues for new treatments.

But research on the genetic basis of mental illness has so far largely excluded populations that are not of European heritage. That means this Kenyan family, and other people of African descent, might not benefit from new biological insights about mental illness.

To help remedy this problem in psychiatric research, researchers from the United States and four African countries are working together to study the genetics of schizophrenia and bipolar disorder. They come from Harvard’s TH Chan School of Public Health and the Broad Institute at MIT in the United States, Moi University and the KEMRI-Wellcome Trust in Kenya, Makerere University in Uganda, and Addis Ababa University in Ethiopia. Rounding out South Africa is the team from the University of Cape Town.

The initiative aims to do something that has never been done before on this scale: recruit 35,000 people in Ethiopia, Kenya, South Africa and Uganda to answer questions about their health, lifestyle and mental illness, and donate two teaspoons of saliva to DNA testing.

Diversity problem

The finding that severe and chronic mental illnesses tend to run in families has spurred efforts to understand the genetic differences between people with these illnesses and those without. By looking at the DNA and unraveling what is failing in the brain that causes these mental disorders, we hope to stimulate the creation of new drugs to treat these debilitating diseases and reduce the suffering that accompanies them.

Unfortunately, recent efforts to study the genetics of a number of diseases have what many of us call a “diversity problem.” Most of the work in human genetics so far has focused on people of Northern European descent, skewing the data in a way that makes it less useful to most people in the world.

The world is dangerously close to an era of “white-only DNA testing.” In existing databases, 78% of the DNA data comes from people of European descent, who represent only about 16% of the world’s population.

One of the main problems with this diversity problem is that any solution (including new drugs) is likely to work better for the people on whose DNA the research was based – people of European descent. In fact, the majority of residents of a diverse city like the American city of Boston, made up of white, black, Hispanic, and Asian people, among others, may not benefit as they could from research efforts emanating from just a part of the world population.

Potential targets for new drugs

Our large collaborative effort in Africa is called Neuropsychiatric Genetics of African Populations-Psychosis, “NeuroGAP-Psychosis” for short.

Using the data collected from the 35,000 people recruited for the project, we will look for clinically relevant and important genetic differences that could be found in people of African descent and may be less common in people of European descent.