A twin study of heritability of plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) mass and activity.

Objective: We investigated heritability of plasma levels (mass) and activity of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)).

Materials And Methods: In 54 healthy twins pairs we estimated genetic variance and heritability of Lp-PLA(2) mass and activity using maximum likelihood and least squares methods. We estimated intra-class correlation (ICC) and proportion of additive genetic variance from a model comprising additive genetic influence (A), environmental effect common to cotwins (C) and individually unique environmental (E) influence (ACE) model.

Results: Twenty-six twin pairs were monozygotic (MZ) and 28 dizygotic (DZ). The Lp-PLA(2) mass and activity showed a significant correlation (r=0.87, p<0.001) and the mean values were similar in MZ and DZ. ICC estimates of heritability for Lp-PLA(2) were 0.27 (mass) and 0.28 (activity); ACE model-based estimates of heritability were 0.37 (mass) and 0.54 (activity). Heritability estimates were not significant for Lp-PLA(2) mass, but significant for Lp-PLA(2) activity.

Conclusions: These results suggest heritability for activity, but not for mass, in healthy Caucasians.