title: Stratifying empiric risk of schizophrenia among first degree relatives using multiple predictors in two independent Indian samples.
abstract: BACKGROUND
  Schizophrenia (SZ) has an estimated heritability of 64-88%, with the higher values based on twin studies. Conventionally, family history of psychosis is the best individual-level predictor of risk, but reliable risk estimates are unavailable for Indian populations. Genetic, environmental, and epigenetic factors are equally important and should be considered when predicting risk in 'at risk' individuals.
  
  
  OBJECTIVE
  To estimate risk based on an Indian schizophrenia participant's family history combined with selected demographic factors.
  
  
  METHODS
  To incorporate variables in addition to family history, and to stratify risk, we constructed a regression equation that included demographic variables in addition to family history. The equation was tested in two independent Indian samples: (i) an initial sample of SZ participants (N=128) with one sibling or offspring; (ii) a second, independent sample consisting of multiply affected families (N=138 families, with two or more sibs/offspring affected with SZ).
  
  
  RESULTS
  The overall estimated risk was 4.31±0.27 (mean±standard deviation). There were 19 (14.8%) individuals in the high risk group, 75 (58.6%) in the moderate risk and 34 (26.6%) in the above average risk (in Sample A). In the validation sample, risks were distributed as: high (45%), moderate (38%) and above average (17%). Consistent risk estimates were obtained from both samples using the regression equation.
  
  
  CONCLUSIONS
  Familial risk can be combined with demographic factors to estimate risk for SZ in India. If replicated, the proposed stratification of risk may be easier and more realistic for family members.
authors.affiliation: Indo-US Projects, Department of Psychiatry, PGIMER-Dr. Ram Manohar Lohia Hospital, Park Street, New- Delhi 110001, India. Electronic address: bhatiatriptish@yahoo.co.in.
authors.forename: Triptish
authors.initials: T
authors.lastname: Bhatia
authors.affiliation: Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh. PA 15261, USA. Electronic address: bgettig@pitt.edu.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Gettig
authors.affiliation: University of Minnesota Medical School-twin cities, Senior Fellow in Department of Psychology, Sherrell J. Aston Professor of Psychology Emeritus, University of Virginia, Charlottesville, VA, USA. Electronic address: gotte003@umn.edu.
authors.forename: Irving I
authors.initials: II
authors.lastname: Gottesman
authors.affiliation: Princeton University, Greater Philadelphia Area, Philadelphia, PA, USA. Electronic address: j.s.berliner@gmail.com.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Berliner
authors.affiliation: Dept. of Psychology L.S.College, Muzaffarpur, B.R.A.Bihar University, Muzaffarpur Bihar, India. Electronic address: drmishrarml@yahoo.com.
authors.forename: N N
authors.initials: NN
authors.lastname: Mishra
authors.affiliation: Departments of Psychiatry and Human Genetics, University of Pittsburgh, School of Medicine and Graduate School of Public Health, Pittsburgh, PA 15213 USA. Electronic address: VishwajitNL@upmc.edu.
authors.forename: Vishwajit L
authors.initials: VL
authors.lastname: Nimgaonkar
authors.affiliation: Department of Psychiatry, PGIMER-Dr. Ram Manohar Lohia Hospital, Park Street, New Delhi 110001, India. Electronic address: smitadeshp@gmail.com.
authors.forename: Smita N
authors.initials: SN
authors.lastname: Deshpande
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012559:Schizophrenia / Q000453:epidemiology* / Q000235:genetics*; D055815:Young Adult
keywords: Familial; Genetic counseling; Risk; Schizophrenia