title: Evidence for a strong genetic influence on carotid plaque characteristics: an international twin study.
abstract: OBJECTIVE
  Few family studies reported moderate genetic impact on the presence and scores of carotid plaques. However, the heritability of carotid plaque characteristics remains still unclear. Twin studies more reliably estimate the relative contribution of genes to these traits in contrast to family study design.
  
  
  METHODS
  One hundred ninety-two monozygotic and 83 dizygotic adult twin pairs (age 49±15 years) from Italy, Hungary, and the United States underwent B-mode and color Doppler ultrasound of bilateral common, internal, and external carotid arteries.
  
  
  RESULTS
  Age-, sex-, and country-adjusted heritability was 78% for the presence of carotid plaque (95% CI, 55%-90%), 74% for plaque echogenicity (hypoechoic, hyperechoic, or mixed; 95% CI, 38%-87%), 69% for plaque size (area in mm2 in longitudinal plane; <or>50 percentile; 95% CI, 16%-86%), 74% for plaque sidedness (unilateral or bilateral; 95% CI, 25%-90%), 74% for plaque numerosity (95% CI, 26%-86%), 68% (95% CI, 40%-84%), and 66% (95% CI, 32%-90%) for the presence of plaque in carotid bulbs and proximal internal carotid arteries. No role of shared environmental factors was found. Unique environmental factors were responsible for the remaining variance (22%-34%). Controlling for relevant covariates did not change the results significantly.
  
  
  CONCLUSIONS
  The heritability of ultrasound characteristics of carotid plaque is high. Unshared environmental effects account for a modest portion of the variance. Our findings should stimulate the search for genes responsible for these traits.
authors.affiliation: Department of Radiology and Oncotherapy, Semmelweis University, and Department of Cardiology, Military Hospital, 78/a Ulloi St, Budapest, H-1082, Hungary. tarnoki2@gmail.com
authors.forename: Adam Domonkos
authors.initials: AD
authors.lastname: Tarnoki
authors.forename: Claudio
authors.initials: C
authors.lastname: Baracchini
authors.forename: David Laszlo
authors.initials: DL
authors.lastname: Tarnoki
authors.forename: Pierleone
authors.initials: P
authors.lastname: Lucatelli
authors.forename: Emanuele
authors.initials: E
authors.lastname: Boatta
authors.forename: Chiara
authors.initials: C
authors.lastname: Zini
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Fanelli
authors.forename: Andrea Agnes
authors.initials: AA
authors.lastname: Molnar
authors.forename: Giorgio
authors.initials: G
authors.lastname: Meneghetti
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Stazi
authors.forename: Emanuela
authors.initials: E
authors.lastname: Medda
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Cotichini
authors.forename: Lorenza
authors.initials: L
authors.lastname: Nisticò
authors.forename: Corrado
authors.initials: C
authors.lastname: Fagnani
authors.forename: Janos
authors.initials: J
authors.lastname: Osztovits
authors.forename: Gyorgy
authors.initials: G
authors.lastname: Jermendy
authors.forename: Istvan
authors.initials: I
authors.lastname: Preda
authors.forename: Robert Gabor
authors.initials: RG
authors.lastname: Kiss
authors.forename: Julia
authors.initials: J
authors.lastname: Metneki
authors.forename: Tamas
authors.initials: T
authors.lastname: Horvath
authors.forename: Giacomo
authors.initials: G
authors.lastname: Pucci
authors.forename: Pal
authors.initials: P
authors.lastname: Bata
authors.forename: Kinga
authors.initials: K
authors.lastname: Karlinger
authors.forename: Levente
authors.initials: L
authors.lastname: Littvay
authors.forename: Viktor
authors.initials: V
authors.lastname: Berczi
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Garami
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Schillaci
mesh_terms: D000328:Adult; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000235:genetics*; D004777:Environment; D005260:Female; D006801:Humans; D006814:Hungary; D038622:Internationality; D007558:Italy; D008297:Male; D008875:Middle Aged; D014429:Twins, Dizygotic / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics; D018608:Ultrasonography, Doppler; D014481:United States