title: Heritability and environmental effects for self-reported periods with stuttering: a twin study from Denmark.
abstract: Genetic influence for stuttering was studied based on adult self-reporting. Using nation-wide questionnaire answers from 33,317 Danish twins, a univariate biometric analysis based on the liability threshold model was performed in order to estimate the heritability of stuttering. The self-reported incidences for stuttering were from less than 4% for females to near 9% for males. Both probandwise concordance rate and tetrachoric correlation were substantially higher for monozygotic compared to dizygotic pairs, indicating substantial genetic influence on individual liability. Univariate biometric analyses showed that additive genetic and unique environmental factors best explained the observed concordance patterns. Heritability estimates for males/females were 0.84/0.81. Moderate unique environmental effects were also found.
authors.affiliation: National Centre for Epidemiology, Surveillance and Health Promotion, National Institute of Health, Rome, Italy.
authors.forename: Corrado
authors.initials: C
authors.lastname: Fagnani
authors.forename: Steen
authors.initials: S
authors.lastname: Fibiger
authors.forename: Axel
authors.initials: A
authors.lastname: Skytthe
authors.forename: Jacob V B
authors.initials: JV
authors.lastname: Hjelmborg
mesh_terms: D000328:Adult; D000368:Aged; D001699:Biometry; D003718:Denmark / Q000453:epidemiology; D004777:Environment; D005260:Female; D020022:Genetic Predisposition to Disease; D040941:Heredity; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D010641:Phenotype; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D057566:Self Report; D013342:Stuttering / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology; D014429:Twins, Dizygotic / Q000235:genetics* / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics* / Q000523:psychology