Is reduced dermatoglyphic a-b ridge count a reliable marker of developmental impairment in schizophrenia?

Background: Finger and hand prints are formed during the late first and sec ond trimester of foetal development, after which they remain unchanged. The ir expression may be influenced by both genetic and environmental factors. Some studies have suggested that a reduced total finger ridge count (TFRC) and, in particular, a reduce total a-b ridge count (TABRC), may be associat ed with schizophrenia. Aim: To study these two variables in a large, ethnic ally homogenous sample and to compare our findings with those of other rece nt studies. Method: Finger and hand prints of 150 people with DSM-III-R sch izophrenia were compared with those of 92 healthy controls. Results: Patien ts had a reduced mean TABRC (P = 0.03) compared with controls. There was a significant (P = 0.02) linear trend for lower TABRC and increasing incidenc e of schizophrenia (OR linear trend = 1.3; 95% CI 1.1-1.7), implying a cont inuous increase in the risk for schizophrenia with reduction in TABRC. No s ignificant difference between groups was observed for TFRC. Conclusion: The se results provide further evidence that dermatoglyphic abnormalities exist in at least some patients with schizophrenia and that the a-b ridge count may be a marker of disruption, probably environmental, that occurs when the developing brain may also be particularly vulnerable to such insult. These findings support the concept that some cases of schizophrenia may be due t o adverse intrauterine events. (C) 2001 Elsevier Science B.V. All rights re served.