2D:4D finger ratio in Slovak autism spectrum population.

Previous studies have revealed that autism may arise as the result of exposure to high concentrations of prenatal testosterone. Ratio of second and fourth digits (2D:4D) is usually used as a proxy for prenatal testosterone. In this study, 2D:4D in 56 boys with ASD and in 32 control boys was measured. We found that the 2D:4D in ASD boys were lower than the ratio in control boys. These findings are discussed with reference to the "extreme male-brain" theory of autism. Results achieved in this interdisciplinary research are valuable in further biological and psychological approaches in neurocognitive research and diagnostics of children from ASD (Tab. 1, Ref. 38).