Schizophrenia genetics analyzed in South African Xhosa

January 30, 2020

The first genetic analysis of schizophrenia in an ancestral African population, the South African Xhosa, will be published Jan. 31 in Science. An international group of scientists conducted the research.

The study of schizophrenia 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 Xhosa do not have an unusually high risk of schizophrenia.

The relative lack of genetics studies in Africa leaves a major gap in understanding human genetics. Almost 99% of human evolution took place in Africa, after the first modern humans originated and before humans migrated from Africa to Europe and Asia 50,000 to 100,000 years ago. Because of the lack of studies in Africa, many generations of human genetic history are missing from our understanding of human adaptation and of human disease.

The Xhosa trace their history to the migration of Bantu-speaking people from the Great Lakes region of eastern Africa to southern Africa centuries ago. The Xhosa now live throughout South Africa and are the largest population group of the Eastern Cape region.

Schizophrenia affects approximately 1% of people in all parts of the world and is one of the leading causes of disability worldwide. This study revealed that Xhosa individuals with schizophrenia are significantly more likely to carry rare, damaging genetic mutations compared to Xhosa individuals without severe mental illness.

Many of the genes disrupted by the rare damaging mutations of these patients are involved in the organization and function of brain synapses. Synapses coordinate the communication between brain nerve cells called neurons,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, and suggest potential mechanisms for the design of more effective treatments.
-end-
The project was led by Jon McClellan, professor of psychiatry, and Mary-Claire King, professor of genome sciences and of medicine, at the University of Washington School of Medicine in Seattle; Dan Stein, professor and head of psychiatry and mental health at the University of Cape Town, South Africa; and Ezra Susser, professor of epidemiology and psychiatry at the Mailman School of Public Health, Columbia University, New York.

The Xhosa community participated in the development and conduct of the research.

University of Washington Health Sciences/UW Medicine

Related Schizophrenia Articles from Brightsurf:

Schizophrenia: When the thalamus misleads the ear
Scientists at the University of Geneva (UNIGE) and the Synapsy National Centre of Competence in Research (NCCR) have succeeded in linking the onset of auditory hallucinations - one of the most common symptoms of schizophrenia - with the abnormal development of certain substructures of a region deep in the brain called the thalamus.

Unlocking schizophrenia
New research, led by Prof. LIU Bing and Prof. JIANG Tianzi from the Institute of Automation of the Chinese Academy of Sciences and their collaborators have recently developed a novel imaging marker that may help in the personalized medicine of psychiatric disorders.

Researchers discover second type of schizophrenia
In a study of more than 300 patients from three continents, over one third had brains that looked similar to healthy people.

New clues into the genetic origins of schizophrenia
The first genetic analysis of schizophrenia in an ancestral African population, the South African Xhosa, appears in the Jan.

Dietary supplement may help with schizophrenia
A dietary supplement, sarcosine, may help with schizophrenia as part of a holistic approach complementing antipsychotic medication, according to a UCL researcher.

Schizophrenia: Adolescence is the game-changer
Schizophrenia may be related to the deletion syndrome. However, not everyone who has the syndrome necessarily develops psychotic symptoms.

Study suggests overdiagnosis of schizophrenia
In a small study of patients referred to the Johns Hopkins Early Psychosis Intervention Clinic (EPIC), Johns Hopkins Medicine researchers report that about half the people referred to the clinic with a schizophrenia diagnosis didn't actually have schizophrenia.

The ways of wisdom in schizophrenia
Researchers at UC San Diego School of Medicine report that persons with schizophrenia scored lower on a wisdom assessment than non-psychiatric comparison participants, but that there was considerable variability in levels of wisdom, and those with higher scores displayed fewer psychotic symptoms.

Recognizing the uniqueness of different individuals with schizophrenia
Individuals diagnosed with schizophrenia differ greatly from one another. Researchers from Radboud university medical center, along with colleagues from England and Norway, have demonstrated that very few identical brain differences are shared amongst different patients.

Resynchronizing neurons to erase schizophrenia
Today, a decisive step in understanding schizophrenia has been taken.

Read More: Schizophrenia News and Schizophrenia Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.