title: Neuropsychological performance as endophenotypes in extended schizophrenia families from the Central Valley of Costa Rica.
abstract: OBJECTIVE
  The understanding of complex heritable psychiatric disorders such as schizophrenia could be clarified by examining endophenotypes within genetically isolated populations, such as the one found in the Central Valley of Costa Rica. The reduction of familial variability within a sample could allow the relationship between the cognitive and symptomatic manifestations of the illness and the genetic underpinnings to become more observable. This study investigates the neuropsychological test performances of 41 family members from four extended multiplex families within the Spanish origin population of the Central Valley of Costa Rica as potential endophenotypes for genetic studies.
  
  
  METHODS
  Individuals with a diagnosis of schizophrenia or schizoaffective disorder were compared with unaffected relatives and 15 unrelated controls with no family history of schizophrenia.
  
  
  RESULTS
  Although the sample size is small, the results confirm previous reports in the literature of deficits in working memory, executive function, processing speed, and verbal fluency in individuals with schizophrenia compared with controls and intermediate performance in nonpsychotic family members compared with controls. We also found several suggestive quantitative cognitive trait loci with log of the odds greater than 1.75.
  
  
  CONCLUSIONS
  These findings suggest that the cognitive deficits in schizophrenia are consistent aspects of the illness, although their usefulness as endophenotypes for genetic studies remains unclear.
authors.affiliation: Department of Psychiatry, New York University School of Medicine, New York 10016, USA. hcbertisch@yahoo.com
authors.forename: Hilary
authors.initials: H
authors.lastname: Bertisch
authors.forename: Andrea
authors.initials: A
authors.lastname: Mesen-Fainardi
authors.forename: Maureen V
authors.initials: MV
authors.lastname: Martin
authors.forename: Vanessa
authors.initials: V
authors.lastname: Pérez-Vargas
authors.forename: Tatiana
authors.initials: T
authors.lastname: Vargas-Rodríguez
authors.forename: Gabriela
authors.initials: G
authors.lastname: Delgado
authors.forename: Camila
authors.initials: C
authors.lastname: Delgado
authors.forename: Michele
authors.initials: M
authors.lastname: Llach
authors.forename: Beatrice
authors.initials: B
authors.lastname: LaPrade
authors.forename: William
authors.initials: W
authors.lastname: Byerley
authors.forename: William E
authors.initials: WE
authors.lastname: Bunney
authors.forename: Marquis P
authors.initials: MP
authors.lastname: Vawter
authors.forename: Lynn E
authors.initials: LE
authors.lastname: DeLisi
mesh_terms: D003071:Cognition; D003364:Costa Rica; D003710:Demography; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010375:Pedigree; D010641:Phenotype; D040641:Quantitative Trait Loci / Q000235:genetics; D012559:Schizophrenia / Q000235:genetics / Q000473:pathology*