title: A family genetic study of clinical subtypes of obsessive-compulsive disorder.
abstract: OBJECTIVE
  The results of various family studies of obsessive-compulsive disorder have varied widely, possibly because of heterogeneity in the obsessive-compulsive disorder phenotype. The current study was conducted to determine familiality of checker and washer subtypes of obsessive-compulsive disorder compared with normal controls.
  
  
  METHODS
  In this study, all available first-degree relatives of 25 checker, 34 washer and 40 psychiatrically normal control probands were interviewed directly, using structured interviews.
  
  
  RESULTS
  The morbid risk of syndromal and subsyndromal obsessive-compulsive disorder was significantly greater among the relatives of checker probands (19.4%) than in the relatives of washer (8.7%) or control probands (5.4%), while the morbid risk for the relatives of washer and control probands was not significantly different. In all, 67% of the checker relatives with syndromal and subsyndromal obsessive-compulsive disorder were checkers, while 54% of the washer relatives with syndromal and subsyndromal obsessive-compulsive disorder were washers.
  
  
  CONCLUSIONS
  Our study provides preliminary evidence of familiality of the checker subtype of obsessive-compulsive disorder. Future studies using patients subtyped on the basis of symptom dimensions, in larger obsessive-compulsive disorder samples, are needed, to further validate the genetic basis of obsessive-compulsive disorder.
authors.affiliation: Institute of Psychiatry, London, UK. S.Bhattacharyya@iop.kcl.ac.uk
authors.forename: Sagnik
authors.initials: S
authors.lastname: Bhattacharyya
authors.forename: Channarayapatna Lakshmi Narasimha
authors.initials: CL
authors.lastname: Prasanna
authors.forename: Sumant
authors.initials: S
authors.lastname: Khanna
authors.forename: Yemiganur Chendrashekhar
authors.initials: YC
authors.lastname: Janardhan Reddy
authors.forename: Shekhar
authors.initials: S
authors.lastname: Sheshadri
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000145:classification / Q000235:genetics*