title: Quantitative genetic study of amphiregulin and fractalkine circulating levels--potential markers of arthropathies.
abstract: OBJECTIVE
  Amphiregulin (AREG) and Fractalkine (FRACT), are involved in a variety of normal and pathological processes, and are both suggested to be relevant to joint degeneration. The aims of the present study included (1) testing association between circulating levels of these biomarkers and joint pathologies, (2) evaluation of the putative genetic and familial factors' effect on AREG and FRACT variability.
  
  
  METHODS
  The study was conducted in the family-based sample of 923 Caucasian individuals. Variance component analysis was used to assess contribution of genetic and environmental factors to variability of AREG and FRACT concentration.
  
  
  RESULTS
  The mean levels of FRACT were significantly higher in the affected group with arthropathies (synovial joints osteoarthritis (OA) and disc degenerative disease, DDD) then in the control group (P<0.0004). Circulating AREG levels were higher in DDD (P=0.0272). Genetic factors constituted the main source of the interindividual differences of the AREG and FRACT levels in our sample, and explained 29.68% and 41.68% of the total variation, respectively. The phenotypic correlation between AREG and FRACT was substantial (r=0.55, P=0.0001) and was associated with both common genetic and environmental factors. Specifically, 30% of the phenotypic correlation between AREG and FRACT was due to common genetic effects.
  
  
  CONCLUSIONS
  Further studies are required to assess relevancy of FRACT to clinical diagnosis and prognosis of arthropathies, to investigate the mechanisms behind the observed phenotypic and genetic covariation among the studied biomarkers, and to explore specific genetic polymorphisms affecting AREG and FRACT variation.
authors.affiliation: Human Population Biology Research Unit, Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: A
authors.initials: A
authors.lastname: Leonov
authors.forename: S
authors.initials: S
authors.lastname: Trofimov
authors.forename: S
authors.initials: S
authors.lastname: Ermakov
authors.forename: G
authors.initials: G
authors.lastname: Livshits
mesh_terms: D066258:Amphiregulin; D000704:Analysis of Variance; D015415:Biomarkers / Q000378:metabolism; D054428:Chemokine CX3CL1 / Q000235:genetics* / Q000378:metabolism*; D066255:EGF Family of Proteins; D005260:Female; D020022:Genetic Predisposition to Disease; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism*; D007592:Joint Diseases / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D010003:Osteoarthritis / Q000235:genetics* / Q000378:metabolism*; D011110:Polymorphism, Genetic
chemical_list: C587848:AREG protein, human; D066258:Amphiregulin; D015415:Biomarkers; D054428:Chemokine CX3CL1; D066255:EGF Family of Proteins; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins