April 09, 2007

Schizophrenia Risk Genes Potentially Identified for Hispanic Populations

In a newly announced study three regions of chromosomes were identified that were estimated to hold risk genes for schizophrenia in hispanic families.

In the study genetic material (DNA) was analyzed from 459 individuals of Hispanic ancestry from 99 families, containing at least two siblings with hospital diagnoses of schizophrenia or schizo affective disorder in order to determine gene regions that are likely contributing to the development of these psychotic disorders.

Three regions of chromosomes 1, 5 and 18 were found to very likely contain genes that contribute to schizophrenia in persons of Mexican and Central American ancestry, investigators of an international genetics study conducted in the U.S., Mexico, Guatemala and Costa Rica reported this month.

The study, led by Michael A. Escamilla, M.D., of The University of Texas Health Science Center at San Antonio and funded by the National Institute of Mental Health Genetics Initiative, was published in the American Journal of Medical Genetics. The study also included participation by the Southwest Foundation for Biomedical Research in San Antonio.

“Genome” describes the total contents of a person’s genetic material, or DNA. Scientists perform genome-wide scans to identify DNA variations that are unique to distinct people groups. In recent years, similar studies in the United Kingdom, Iceland and Canada utilized genome-wide scans to identify genes causing schizophrenia, but this type of work had not been done in the U.S. Latino population or in the Mexican population, Dr. Escamilla said.

The researchers studied 459 individuals from 99 families that had at least two siblings with schizophrenia or schizoaffective disorder. The team used more than 400 DNA markers, which are distinguishing landmarks across the genome, to identify the regions most likely to contain schizophrenia-susceptibility genes.

Two of the regions of DNA are distinct from regions that have been identified as containing schizophrenia-risk genes in studies of European, African American and European American ancestry, while one overlaps from a recent study that looks at Americans of European and African ancestry.

The findings are an important step toward identifying genes that affect a person’s risks for developing schizophrenia and other related psychotic disorders, and offer hope that the biological causes of these disorders in the Latino population will eventually be identified.

“The results of this study represent years of work at the international level, and the efforts of hundreds of research staff and participating families in the Southwestern United States, Mexico, Costa Rica and Guatemala,” Dr. Escamilla said. “Individuals and families in the Latino community carry great burdens associated with schizophrenia and have historically not been able to benefit from the recent advances in genetic research that we have seen in other populations. The fact that the National Institute of Mental Health has funded and supported this research work shows its commitment to helping study these diseases in persons of all ethnic heritage in the United States.”

Watch News Video: Schizophrenia genes discovered (San Antonio, Texas KENS channel 5)

Source Abstract: A genome-wide scan for schizophrenia and psychosis susceptibility loci in families of Mexican and Central American ancestry

Related Reading:
Ethnicity Affects Antipsychotic Response

Family warmth in schizophrenia

Ethnicity and Schizophrenia Diagnosis


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