Genetic heritability and shared environmental factors among twin pairs with autism.
Arch Gen Psychiatry
; 68(11): 1095-102, 2011 Nov.
Article
em En
| MEDLINE
| ID: mdl-21727249
ABSTRACT
CONTEXT Autism is considered the most heritable of neurodevelopmental disorders, mainly because of the large difference in concordance rates between monozygotic and dizygotic twins. OBJECTIVE:
To provide rigorous quantitative estimates of genetic heritability of autism and the effects of shared environment. DESIGN, SETTING, ANDPARTICIPANTS:
Twin pairs with at least 1 twin with an autism spectrum disorder (ASD) born between 1987 and 2004 were identified through the California Department of Developmental Services. MAIN OUTCOMEMEASURES:
Structured diagnostic assessments (Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule) were completed on 192 twin pairs. Concordance rates were calculated and parametric models were fitted for 2 definitions, 1 narrow (strict autism) and 1 broad (ASD).RESULTS:
For strict autism, probandwise concordance for male twins was 0.58 for 40 monozygotic pairs (95% confidence interval [CI], 0.42-0.74) and 0.21 for 31 dizygotic pairs (95% CI, 0.09-0.43); for female twins, the concordance was 0.60 for 7 monozygotic pairs (95% CI, 0.28-0.90) and 0.27 for 10 dizygotic pairs (95% CI, 0.09-0.69). For ASD, the probandwise concordance for male twins was 0.77 for 45 monozygotic pairs (95% CI, 0.65-0.86) and 0.31 for 45 dizygotic pairs (95% CI, 0.16-0.46); for female twins, the concordance was 0.50 for 9 monozygotic pairs (95% CI, 0.16-0.84) and 0.36 for 13 dizygotic pairs (95% CI, 0.11-0.60). A large proportion of the variance in liability can be explained by shared environmental factors (55%; 95% CI, 9%-81% for autism and 58%; 95% CI, 30%-80% for ASD) in addition to moderate genetic heritability (37%; 95% CI, 8%-84% for autism and 38%; 95% CI, 14%-67% for ASD).CONCLUSION:
Susceptibility to ASD has moderate genetic heritability and a substantial shared twin environmental component.
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Base de dados:
MEDLINE
Assunto principal:
Gêmeos Monozigóticos
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Transtornos Globais do Desenvolvimento Infantil
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Predisposição Genética para Doença
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Interação Gene-Ambiente
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article