International Meeting for Autism Research (London, May 15-17, 2008): Finger length of boys with ASD differs from those with disruptive behavior, anxiety

Finger length of boys with ASD differs from those with disruptive behavior, anxiety

Friday, May 16, 2008
Champagne Terrace/Bordeaux (Novotel London West)
11:30 AM
E. I. De Bruin , Outpatient Department of Child and Adolescent Psychiatry, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
K. Greaves-Lord , Outpatient Department of Child and Adolescent Psychiatry, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
P. F. A. De Nijs , Outpatient Department of Child and Adolescent Psychiatry, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
F. Verheij , Outpatient Department of Child and Adolescent Psychiatry, Erasmus MC-Sophia Children's Hospital, Rotterdam, Netherlands
Background: Over 125 years ago it was already shown that males had longer ring fingers relative to their index fingers, and women showed the reverse pattern. Since then, a large amount of studies have associated the length of the index finger relative to the length of the ring finger, the 2D:4D ratio, with a variety of variables (i.e., assertiveness, breast cancer, attractiveness, fertility, female waist-hip ratio, homosexuality). Finger length is determined by hormonal influences (testosterone) in the first 3 months of pregnancy and remains stable over life. Specific patterns of the 2D:4D ratio have been associated with autism before but the milder form of ASD, PDD-NOS, has not yet been studied and also it is unknown whether certain 2D:4D patterns are specific for ASDs.

Objectives: The aim of this study was to compare finger length in boys with different psychiatric disorders.

Methods: Vernier calipers were used to measure finger length in boys with anxiety disorders (n = 20), ADHD/ODD/CD (n = 60), autism/Asperger syndrome (n = 15), PDD-NOS (n = 60), and were compared to normal controls (n = 90). Only boys were included to rule out the effect of male-female differences in finger length, and the effect of a difference male-female prevalence for the disorders.

Results: Groups differed on 2D:4D ratio for the right hand only. Boys with autism/Asperger syndrome showed the most male-like 2D:4D pattern. They had a lower ratio than boys with PDD-NOS, anxiety disorders, and normal controls. Further, boys with externalizing disorders also showed a more male-oriented finger pattern, with a lower 2D:4D ratio than boys with anxiety disorders and normal control boys. The anxious boys showed the most female-like finger pattern compared to the other groups.

Conclusions: Finger length differs in child psychiatric groups which indicates that different underlying endocrinological factors might play a role.