The first genetic analysis of schizophrenia in an ancestral African population, the South African Xhosa, appears in the journal Science. An international group of scientists conducted the research, including investigators from Columbia University Mailman School of Public Health and New York State Psychiatric Institute, as well as the University of Cape Town and the University of Washington.
The study was carried out in the Xhosa population because Africa is the birthplace of all humans, yet ancestral African populations have rarely been the focus of genetics research. The researchers analyzed blood samples from 909 individuals diagnosed with schizophrenia and 917 controls living in South Africa. Their study revealed that participants with schizophrenia are significantly more likely to carry rare, damaging genetic mutations compared to participants without schizophrenia. These rare mutations were also more likely to affect brain and synaptic function. The organization and firing of neuronal synapses are ultimately responsible for learning, memory, and brain function.
The genes and pathways identified by this research inform the understanding of schizophrenia for all human populations, the researchers say. Further studies in African populations might also suggest potential mechanisms for the design of more effective treatments.
“The presence of only a few DNA variations damaging to synaptic function could have an outsized effect on schizophrenia,” says co-author Dr. Ezra Susser, professor of epidemiology and psychiatry at Columbia University Mailman School and New York State Psychiatric Institute. “While these variants differ from person to person, we believe they may disrupt neural pathways that elevate risk for schizophrenia.”Friday Letter Submission, Publish on February 07