Differentiating between low and high susceptibility to schizophrenia in twins: the significance of dermatoglyphic indices in relation to other determinants of brain development

Both the skin and the brain develop from the same ectoderm and it is though t, therefore, that dermatoglyphics are informative for early disturbances i n brain development in schizophrenia. This study was aimed at investigating the differences in both digital and palmar dermatoglyphic indices between twins discordant for schizophrenia and control twins. Furthermore, the sign ificance of dermatoglyphic indices in relation to other determinants of bra in development with regard to the susceptibility to schizophrenia was inves tigated. Data on dermatoglyphic indices of the hand and the palm were obtai ned from 21 same-sex discordant and 37 same-sex control twins. For 19 disco rdant and 25 control twins, there was also data available on brain volumes. Non-genetic intra-uterine circumstances early in pregnancy (10-13 weeks of gestation) are associated with a susceptibility to schizophrenia, since bo th the twins with schizophrenia and the unaffected co-twins showed more flu ctuating asymmetry of the finger ridges (P < 0.01), and marginally higher a bsolute finger ridge counts (P = 0.06) than control twin pairs. Fluctuating asymmetry of the finger ridges was as important as whole brain and left hi ppocampal volumes in differentiating twins with a high susceptibility to sc hizophrenia from those with a low susceptibility. (C) 2001 Elsevier Science B.V. All rights reserved.