The importance of genetics in understanding the etiology of mental illness has become increasingly clear in recent years, as more evidence has mounted that almost all neuropsychiatric disorders have a genetic component. It has also become clear, however, that these disorders are etiologically complex, and multiple genetic and environmental factors contribute to their makeup. So far, traditional linkage mapping studies have not definitively identified specific disease genes for neuropsychiatric disorders, although some potential candidates have been identified via these methods (e.g. the dysbindin gene in schizophrenia; Straub et al., 2002; Schwab et al., 2003). For this reason, alternative approaches are being attempted, including studies in genetically isolated populations. Because isolated populations have a high degree of genetic homogeneity, their use may simplify the process of identifying disease genes in disorders where multiple genes may play a role. Several areas of Latin America contain genetically isolated populations that are well suited for the study of neuropsychiatric disorders. Genetic studies of several major psychiatric illnesses, including bipolar disorder, major depression, schizophrenia, Tourette Syndrome, alcohol dependence, attention deficit hyperactivity disorder, and obsessive–compulsive disorder, are currently underway in these regions. In this paper we highlight the studies currently being conducted by our groups in the Central Valley of Costa Rica to illustrate the potential advantages of this population for genetic studies.
aDepartment of Psychiatry, University of California, San Diego, CA, USA
bDepartment of Psychiatry, University of California, San Francisco, CA, USA
cCentro de Biología Molecular y Celular de la Universidad de Costa Rica, San José, Costa Rica
dNeurogenetics Laboratory, Department of Psychiatry, The University of Texas Health Science Center, San Antonio, Texas, USA
eHospital CIMA, San José, Costa Rica
fDepartment of Child and Adolescent Psychiatry, University of California, San Francisco, CA, USA
gLaboratory of Neurobehavioral Genetics, Mt Sinai School of Medicine, New York, New York, USA
hCentro Internacional de Control de Estres, Guatemala
iCenter for Neurobehavioral Genetics, Departments of Psychiatry and Human Genetics, University of California, Los Angeles, CA, USA
jEscuela de Medicina, Universidad de Costa Rica, San José, Costa Rica
kDepartment of Medical Statistics, Leiden University Medical Center, Leiden, The Netherlands
Sponsorship: This work was partially supported by a grant from the NIH (RR15533).
Correspondence and requests for reprints to Carol A. Mathews, Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, 0810, La Jolla, CA 92093-0810, USA
Tel: +1 619 725 3522; fax: +1 619 260 8437;
Received 1 June 2002 Accepted 1 March 2003
†This manuscript is dedicated to the memory of Lodewijk Sandkuijl MD., 31st July 1953 – 4th December 2002.