Dermatoglyphic ¯uctuating asymmetry and atypical handedness in schizophrenia James L. Reilly a, * , Peter T. Murphy b , Majella Byrne b , Conall Larkin b , Michael Gill c , Eadbhard O'Callaghan b , Abbie Lane b a Department of Psychology, Gilmer Hall, University of Virginia, Charlottesville, VA 22904-4400, USA b St. John of God Psychiatric Services, Cluain Mhuire Family Centre, Blackrock, County Dublin, Ireland c Department of Psychiatry, Trinity Centre for Health Sciences, St. James's Hospital, Trinity College Dublin, Dublin, Ireland Received 2 July 1999; accepted 18 February 2000 Abstract Atypical handedness and dermatoglyphic abnormalities are hypothesized to re¯ect a neurodevelopmental disturbance in schizophrenia.Developmentalinstability,indexedbydermatoglyphic¯uctuatingasymmetryFA),re¯ectsthedegreetowhich anindividual'sontogeneticprogramismaintainedandprovidesausefulframeworkinwhichtoconsideratypicalhandednessin schizophrenia. Thirty patients diagnosed with schizophrenia were compared with 37 matched healthy controls on levels of dermatoglyphic FA, a demonstration task determining hand preference and a test of relative hand skill. Multivariate analyses established that patients demonstrated greater FA and more atypical hand skill compared with controls. In patients, but not in controls,therewasastrongpositiveassociationbetweenameasureofFAandameasureofatypicalhandskill,suggestingthat thesemarkersofneurodevelopmentaldisturbancearerelatedinschizophrenia.Onameasureofhandpreference,patientswere morelikelythancontrolstobeclassi®edasmixedhandedthaneitherrightorlefthanded.Resultsfromthepresentstudysupport the conjecture of greater developmental instability in schizophrenia affecting neurodevelopmental processes, including those conferring manual dominance. q 2001 Elsevier Science B.V. All rights reserved. Keywords: Dermatoglyphics; Developmental instability; Handedness; Lateralization; Neurodevelopment; Schizophrenia 1. Introduction Whilethereisnosingleneurodevelopmentaltheory of schizophrenia, early developmental disturbances indexed by minor physical anomalies Green et al., 1989a; Lane et al., 1997; O'Callaghan et al., 1995), dermatoglyphicabnormalitiesMarkowandGottesman, 1989; Markow and Wandler, 1986; Mellor, 1992; van Os et al., 1997), and an increase in obstetric and birth complications McNeil, 1991; O'Callaghan et al., 1991) in schizophrenia imply pre- and perinatal developmental disturbances to which the developing CNS is likely to be exposed. Several hypotheses regarding the establishment of cerebral asymmetry and lateralization have been offered as one of the means by which the development of the brain is disturbed in schizophrenia Annett, 1997; Crow et al., 1989a,b; DeLisi et al., 1997; Flor-Henry, 1979). Studiesoflateralizedfunctionsreportthatschizophre- nic patients demonstrate atypical patterns of laterali- zation compared with normal controls Green et al., 1989b;Sakumaetal.,1996).Studiesofhandpreference Schizophrenia Research 50 2001) 159±168 0920-9964/01/$ - see front matter q 2001 Elsevier Science B.V. All rights reserved. PII:S0920-996400)00044-X www.elsevier.com/locate/schres * Corresponding author. Tel.: 11-804-982-4740; fax: 11-804- 982-4766. E-mail address: jreilly@virginia.edu J.L. Reilly).