title: A twin study of heritability of plasma lipoprotein-associated phospholipase A2 (Lp-PLA2) mass and activity.
abstract: OBJECTIVE
  We investigated heritability of plasma levels (mass) and activity of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)).
  
  
  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.
authors.affiliation: Department of Clinical & Experimental Medicine, University of Padova, Italy.
authors.forename: Livia
authors.initials: L
authors.lastname: Lenzini
authors.forename: Katia
authors.initials: K
authors.lastname: Antezza
authors.forename: Brasilina
authors.initials: B
authors.lastname: Caroccia
authors.forename: Robert L
authors.initials: RL
authors.lastname: Wolfert
authors.forename: Radoslaw
authors.initials: R
authors.lastname: Szczech
authors.forename: Maurizio
authors.initials: M
authors.lastname: Cesari
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Narkiewicz
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Williams
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Rossi
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000097:blood* / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D004200:Diseases in Twins; D004777:Environment; D005260:Female; D006801:Humans; D016018:Least-Squares Analysis; D016013:Likelihood Functions; D008074:Lipoproteins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
chemical_list: D008074:Lipoproteins; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase