Epidemiologic study of the sexually dimorphic second to fourth digit ratio (2D:4D) and other finger ratios in Greek population.

The 2nd to 4th digit ratio (2D:4D) is a sexually dimorphic biometric marker, related to prenatal estrogen and testosterone levels in utero, and determined genetically by the HOX genes. 2D:4D presents a population variation, which seems to be dependent on geographical position or ethnicity, and may reflect differences in prenatal steroid hormone levels among different ethnic groups. In view of its clinical importance, this study investigates the 2D:4D ratio, as well as other digit ratios, in Greek population. A sample of 60 Greek men and 60 Greek women (age range 19-25 years) was selected by random procedures. Fingers' length was measured twice, using an electronic vernier calliper (precision 0.01 mm). Men had lower 2D:4D ratio (0.974 +/- 0.035 for the right hand and 0.973 +/- 0.044 for the left hand) than women (1.002 +/- 0.04 for the right hand and 1.001 +/- 0.045 for the left hand). This difference in 2D:4D ratio between sexes was statistically significant (p < 0.0001 for the right hand and p < 0.001 for the left hand). The other digit ratios were also lower in men than women for both hands; this difference was statistically significant for all digit ratios of the right hand and for the 2nd to 3rd (2D:3D) and 2nd to 5th (2D:5D) digit ratios of the left hand. The digit ratios are lateralized and sexually dimorphic in Greek population. The sexual dimorphism of all digit ratios (except 2D:3D) is stronger in right than left hand.