Inheritance of dermatoglyphic traits in twins: Univariate and bivariate variance decomposition analysis

Dermatoglyphic traits in a sample of twins were analyzed to estimate the resemblance between MZ and DZ twins and to evaluate the mode of inheritance by using the maximum likelihood-based Variance decomposition analysis. The additive genetic variance component was significant in both sexes for four traits - PII, AB-RC, RC-HB, and ATD-L. AB- RC and RC-HB had significant sex differences in means, whereas PII and ATD-L did not. The results of the Bivariate Variance decomposition analysis revealed that PII and RC-HB have a significant correlation in both genetic and residual components. Significant correlation in the additive genetic variance between AB-RC and ATD-L was observed. The same analysis only for the females sub-sample in the three traits RBL, RBR and AB-DIS shows that the additive genetic RBR component was significant and the AB-DIS sibling component was not significant while others cannot be constrained to zero. The additive variance for AB- DIS sibling component was not significant. The three components additive, sibling and residual were significantly correlated between each pair of traits revealed by the Bivariate Variance decomposition analysis.