The purpose of this study was to estimate the percentage contribution of genetic and environmental factors to Autism Spectrum Disorder (ASD). Children from Denmark, Finland, Sweden, Israel, and Western Australia who were born between January 1, 1998, and December 31, 2011, were followed up to age 16 years. Data were analyzed from September 23, 2016 through February 4, 2018. The sample consisted of 2,001,631 individuals, of whom 1,027,546 (51.3%) were male. 22,156 subjects were diagnosed with ASD.
Based on population data from these 5 countries, the heritability of ASD was estimated to be approximately 80%, indicating that the variation in ASD occurrence in the population is mostly owing to inherited genetic influences. Maternal effects were minimal and ranged from 0.4% to 1.6%. The results suggest possible modest differences in the sources of ASD risk between countries.
Bai D, Yip BHK, Windham GC, Sourander A, Francis R, Yoffe R, Glasson E, Mahjani B, Suominen A, Leonard H, Gissler M, Buxbaum JD, Wong K, Schendel D, Kodesh A, Breshnahan M, Levine SZ, Parner ET, Hansen SN, Hultman C, Reichenberg A, Sandin S: Association of Genetic and Environmental Factors With Autism in a 5-Country Cohort. JAMA Psychiatry [Epub ahead of print, July 17, 2019; doi: 10.1001/jamapsychiatry.2019.1411 ].