Abstract

A GENOME SCAN OF A LARGE COSTARICAN FAMILY AFFECTED BY SCHIZOPHRENIA.

Mesén, A; Cooper, K, Rodriguez, C; Laprade, B; Llach, M; Bertheau, A; Sanabria, JR; DeLisi, LE; Byerley, William
11th World Congress for Psychiatric Genetics (ISPG). 2003.

In the past 2 years we have been identifying families with multiple ill members with schizophrenia in the relatively isolated population of the Central Valley of Costa Rica 1. Most of our work until recently was concentrated on affected sibling pairs from nuclear families. We have begun to link many families together based on more distant ancestry and have thus far identified 8 large extended families affected with schizophrenia or bipolar disorder. A genome-wide scan has been completed on one such large family (27 members genotyped). All the members participating in the study were interviewed using the DIGS, medical records and RPHQ. IRB approval was obtained from the local authorities and all participants signed written informed consent. Blood samples were drawn and DNA prepared and analyzed at the laboratory of W Byerley in the University of California, Irvine. Both narrow and broad diagnoses were considered as phenotypes. With a narrow diagnosis (schizophrenic and schizoaffective) we identified 12 unaffected, 9 affected and 6 other diagnoses. With a broad diagnosis (schizophrenic, schizoaffective and psychosis NOS) 3 additional individuals were considered affected. Although analyses are not yet complete, with the first 100 markers the highest LOD score was obtained with the narrow diagnosis on chromosome 9 at marker D9S286, LOD score 1.6. These new data does not support our previous findings in 98 nuclear families in which our highest MLS was 1.78 on chromosome 5q 2. Further work analyses of all extended families are in progress. In addition, we plan to use alternative intermediate biological phenotypes using MRI in all 8 families. This aspect of the project has not yet been completed. Acknowledgements: This work was supported by the Pritzker Neuropsychiatric Disorder Research Consortium Fund and NIH Conte grant MH60398-03. We acknowledge participation of all Consortium members in this work.