title: Dermatoglyphics and Schizophrenia: a meta-analysis and investigation of the impact of obstetric complications upon a-b ridge count.
abstract: BACKGROUND
  Patients with schizophrenia show deviances in their dermatoglyphics, in particular reductions in palmar a-b ridge counts (ABRCs), which are evidence of an early developmental deviance. However, the severity or the origin of these ABRC changes has not been established.
  
  
  METHODS
  (i) We examined the published literature on the ABRC in patients with schizophrenia against controls with a random effects meta-analysis. (ii) We used linear regression to study the ABRC in our sample of families including 125 patients with schizophrenia, 107 of their unaffected relatives and 98 controls. (iii) The effect of obstetric complications on the patient's ABRC was examined using the Lewis Murray scale.
  
  
  RESULTS
  The pooled standardised effect size of ABRC differences between patients and controls obtained by our meta-analysis was 0.39 (95% CI: 0.05-0.73; p=0.03). In our sample, there were no significant differences in ABRCs between those with schizophrenia, their relatives and controls. Only those patients with obstetric complications had significantly reduced ABRC compared to controls (p=0.01).
  
  
  CONCLUSIONS
  We confirmed the presence of significant yet mild ABRC reductions in schizophrenia. These represent a subtle deviance from the norm and could be present in certain subsets of patients, possibly those who suffered early developmental insults.
authors.affiliation: Division of Psychological Medicine, Institute of Psychiatry, P.O. Box 63, De Crespigny Park, London SE5 8AF, UK. e.bramon@iop.kcl.ac.uk
authors.forename: Elvira
authors.initials: E
authors.lastname: Bramon
authors.forename: Muriel
authors.initials: M
authors.lastname: Walshe
authors.forename: Colm
authors.initials: C
authors.lastname: McDonald
authors.forename: Beatriz
authors.initials: B
authors.lastname: Martín
authors.forename: Timothea
authors.initials: T
authors.lastname: Toulopoulou
authors.forename: Harvey
authors.initials: H
authors.lastname: Wickham
authors.forename: Jim
authors.initials: J
authors.lastname: van Os
authors.forename: Paul
authors.initials: P
authors.lastname: Fearon
authors.forename: Pak C
authors.initials: PC
authors.lastname: Sham
authors.forename: Lourdes
authors.initials: L
authors.lastname: Fañanás
authors.forename: Robin M
authors.initials: RM
authors.lastname: Murray
mesh_terms: D003878:Dermatoglyphics; D005260:Female; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology*; D012559:Schizophrenia / Q000209:etiology* / Q000503:physiopathology*