Heritability assessment of cartilage metabolism. A twin study on circulating procollagen IIA N-terminal propeptide (PIIANP)

SummaryObjectiveThe aim of this investigation was to estimate the heritability of circulating collagen IIA N-terminal propeptide (PIIANP) by studying mono- and dizygotic healthy twin pairs at different age and both genders.Design598 monozygotic (MZ) and dizygotic (DZ) twin individuals aged 18–59 years were recruited from the Danish Twin Registry. PIIANP was measured by competitive ELISA. The similarity of circulating PIIANP among MZ and DZ twins was assessed by intraclass correlations according to traits. The heritability was estimated by variance component analysis accounting for additive and dominant genetic factors as well as shared and non-shared environment but ignoring epistasis (genetic inter-locus interaction) and gene–environment interaction.ResultsThe intraclass correlation of PIIANP in MZ and DZ twins was 0.69 (0.60–0.76) and 0.46 (0.34–0.58) respectively indicating a significant genetic impact on PIIANP in serum. Additive genetic effects explained 45% (21–70%), shared environment 24% (7–53%) and non-shared environment 31% (24–39%) of the total variance. The heritability estimate did not differ across ages and between genders.ConclusionsThe study shows that approximately 45% of the collagen IIA synthesis as assessed by the collagen IIA N-terminal propeptide in serum is attributable to genetic effectors while individual and shared environment account for 24% and 31% respectively. The heritability does not differ between genders or according to age

Rokhlin Dimension for Flows

This research was supported by GIF Grant 1137/2011, SFB 878 Groups, Geometry and Actions and ERC Grant No. 267079. Part of the research was conducted at the Fields institute during the 2014 thematic program on abstract harmonic analysis, Banach and operator algebras, and at the Mittag–Leffler institute during the 2016 program on Classification of Operator Algebras: Complexity, Rigidity, and Dynamics.Peer reviewedPostprin

Handling blood cell composition in epigenetic studies on ageing

Molecular Epidemiolog